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Local climate in the region: 1955 Boyd, D. W.

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LOCAL OLIMATE IN THE OTTAWA REGION:1955

by D. W. Boyd

Report No. 125 of the D1vision of Building Research

Ottawa July 1957 50' 40'

WEATHER STATiONS IN THE OTTAWA REGION

• PRECIPITATION ONLY • PRECIPITATION a TEMP.

I N.R.C. 6 10 BECKWITH 2 ROCKCLIFFE 7 LONG ISLAND II LA SALLE 3 AIRPORT 8 MANOTICK 12 LEMIEUX IS. 4 EXP. FARM 9 ORLEANS 13 SHIRLEY BAY 5 CITY VIEW 14 BAYVIEW

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o I 2 3 4 5 MILES 50' 40'

D.B.R INT. RPT. NO. 125 PREFACE

This report is a further record of the detailed studies being made of the climate of the Ottawa region by the Division of Building Research in connection with its over-all investigation of climate in relation to building. The author, Donald W. Boyd, serves as full-time climatologist to the Division being seconded to this post from his official position with the Meteorological Branch of the Department of Transport by kind permission of Mr. Andrew Thomson, Director. This very close liaison is a continuing source of satisfaction to the Division of Building Research. The Division is most grateful to the volunteer observers in the Ottawa district whose work has made the preparation of this report possible. It is hoped that when they see this record of the consolidated results, they will feel encouraged and realize that their ovm individual observations are greatly assisting in the development of a clear picture of the climate of the Ottawa region.

Ottawa July 1957 R. F. Legget, Director. LOCAL ｃｌｉｮｾｔｅ IN THE OTTAWA REGION: 1955 by

Donald W. Boyd

This is the fourth of a series of annual reports based on weather observations in and near the City of Ottawa. During these years the number of precipitation observing stations in. the region has increased. In the first ｾｶｯ reports (DBR Reports S-36 and R. ,,46) for 1952 and 1953 there were only four precipi• tation stations; by 1954 (DBR Report No. 70) the number had jumped to eleven, and in the present report thirteen stations are included. The same is not true for temperature observations. Since 1952 there have been four stations observing maximum and minimum temperatures in standard Stevenson screens. Values for a fifth station observing only hourly temperatures in a small screen on the side of a bUilding were included in last year's report and in the present one. Reliable wind observations in 1955 are available only from the two airports. The anemometer at the N.R.C. station was not operating satisfactorily and even for those months when the reports were complete the observations are suspected of being biased. . The locations of the observing stations are indicated on the map. Some notes about their names, observers and exposures are contained in the appendiX. Each part of this report deals with a single weather element and is based on the observations taken at all those stations the records of which are complete or nearly complete. It is difficult to use incomplete records because some estimate must be made for the missing data. One day or one month can- ll not be just 1l1eft out , because averaging the remaining data is the same as assuming that the missing value was the same as the average. A better estimate can usually be made by the obser• ver. Since 1953 the Climatological Division has been using normal temperature and precipitation values based on the standard thirty-year period from 1921 to 1950. As mentioned in Report No. 70 for 1954, the only station in the Ottawa region with observations throughout this period is the Central Experi• mental Farm. As in the reports for the last two years the temperature and precipitation observations at the Farm for the current year are compared with the standard normal values at - 2 -

the same station, as an indication of hor: 1955 departed from normal. The best wind records in this region are for Ottawa Airport. All the observations from 1939 to 1954 inclusive have been averaged to give the sixteen-year normal values.

PART OIrE : TEMPERATURE At four of the weather stations in Ottawa the maximum and minimum thermometers are read and reset at least twice a day, at 0730 and 1930 E. S. T., or as close to these times as is practical. The minimum temperature reported for the day is the lower of the two (or the lowest of four) readings taken on that calendar day. In other words, it is the lowest tem• perature in the 24-hour period ending at the time of the evening observation. The maximum temperature reported for the day is the higher of the readings taken in the evening and the next morning (or the highest of four readings ending with the one at 0730 E.S.T.'. Thus it is the highest temperature in the 24-hour period which does not end until the time of the obser• vation the following morning. At Bayview the actual temperature is read once each hour. The daily minimum temperature is the lowest of the 25 readings ending with the one at 2000 E.S.T. The daily maximum is the highest of the 25 readings ending with the one at 0800 E.S.T. the following day. Extreme Temperatures Temperature records from all the stations at Ottawa (including some which are now closed but whose observations go back as far as 1872) have :been searched for the highest and lowest temperatures ever reported in each month. These record extremes are tabulated in the first and last lines of Table I. The rest of Table I is based entirely on the daily maximum and minimum temperatures observed in 1955. Four values are tabulated for each station and for each month. The first and last .groups, the monthly maxima and the monthly minima, are respectively, the highest of the daily maxima and the lowest of the daily minima in each month. The second and third groups, the mean daily maxima and the mean daily minima are the averages for the month of the daily maxima and minima res• pectively. No new record monthly maxima or minima were established or equalled in 1955, although the maxima at Rockcliffe and Bayview in July and August and the Experimental Farm in August all came within one degree of the previous records. The minima were all at least six degrees above the previous records. - 3 -

Mean Temperatures The mean temperature for a day is often defined as the average of the maximum and minimum. Hence the monthly mean temperatures are the averages of the monthly mean daily maxima and minima. These monthly means for 1955 are shown in Table II. Since the values for Bayview were obtained in a different way, they have not been used in computing the average for the region of the monthly mean temperatures. The second section of Table II lists the differences between the mean temperatures for the individual stations and the average mean temperatures for the region in 1955. Rockcliffe temperatures were above the average in every month, and N.R.C.'s, average or above. The Experimental Farm and the Airport were below the average throughout the year. With the exception of Rockcliffe in 1mrch, none of the differences was more than one degree. The differences from the average for the year as a whole for these four stations are tabulated below with similar values taken from the reports for the three previous years: 1952 1953 1954 1955 Average N.R.C. 0.3 0.2 0.4 0.2 0.3 Rockc1iffe 0.5 0.5 0.7 0.8 0.6 Airport -0.5 -0.3 -0.6 -0.4 -0.5 Exp. Farm -0.3 -0.3 -0.4 -0.6 -0.4 These differences are all small, averaging less than half a degree. However, their consistency from year to year indicates that they represent a real difference in the local climate of the region. On the average Rockcliffe and N.R.C. are about a degree warmer than the Airport and the Experimental Farm. The temperature reports from BaYView are about three degrees warmer than the average of the "other four stations. This large difference is quite likely caused partly by the different method of obtaining the mean temperatures and partly by the urban effect. An indication of how 1955 temperatures departed from the normal is given in the last section of Table II. These temperatures are all for the Experimental Farm but the differences from normal for the other stations would be very nearly the same because of the relatively constant differences between the mean temperatures at the Farm and at the other stations. The year as a whole was a degree and a half above normal. This was a little warmer than the previous year, 1954, but not as warm as 1952 and 1953 which were three or four degrees - 4 - above normal. January, March, and December were the only months in 1955 that were much below normal. The five months from April to August were all well above normal and averaged four and a half degrees above. Daily Temperatures at N.R.C. and Rockcliffe In the reports for the last three years a detailed study has been made of the daily maximum and minimum tempera• tures at N.R.C. compared to those at Rockcliffe. A similar study has been made of the 1955 temperatures and the results for the three years 1953 to 1955 are plotted in Fig. 1. Each plotted point represents the mean of about fifteen readings of the maximum (or minimum) temperature at Rockcliffe and the mean of the corresponding differences between the maxima (or minima) at N.R.C. and Rockcliffe. The inclusion of the 1955 data tends to confirm the previous conclusion that maximum temperatures are significantly higher at Rockcliffe particularly in warm weather. Nothing ｯｾｳｩｶ･ can be said about the differences in the minimum temperatures.

PAL'1T TWO : PRECIPITATION Measurements of rainfall and snowfall are made either twice or four times a day at most of the Ottawa stations at the same times as the thermometers are read. The "precipitation day" is the same as the day for maximum temperature. That is, the total precipitation for the day is the sum of all the amounts which fall from about 0730 E.S.T. in the morning until about 0730 the following morning. Rainfall and Total Precipitation In 1955 there were ten stations in the Ottawa region that reported precipitation every month. Three other stations each missed one month. The monthly rainfalls for all these stations are tabulated in Table III and the monthly total precipitations in Table IV with the values for missing or in• complete reports estimated in each case. Table III also gives the average for the thirteen stations of the rainfall for each month and the rainfall at BaYView during the summer. Table IV includes the average for the thirteen stations of the total precipitation for each month and for the year. This total precipitation is the sum of the snowfall divided by ten and the actual rainfall. The column at the extreme right is the annual total precipitation expressed as a percentage of the thirteen-station average. - 5 -

Rockcliffe had the most precipitation during the year, but was not much ahead of Lemieux Island and Long Island. Orleans was at the dry end of the list with only 80 per cent of the average. This low value may be partly due to the very exposed location of the rain gauge. Although the heaviest precipitation was near the there does not seem to be any simple precipitation pattern for the region; no doubt it is masked by larger random variations. The four older stations can be compared over a longer period which shows some persistence. If the total annual precipitations for these four stations are averaged and sub• tracted from the individual readings for each of the last four years, the following values are obtained: 1952 1953 1954 ill2 Average N.R.C. -0.86 -2.66 -2.24 -3.21 -2.24 Rockcliffe 1.25 1.90 2.33 3.15 2.16 Airport 1.19 0.12 2.23 0.19 0.93 Exp. Farm -1.59 0.65 -2.31 -0.13 -0.85 During these four years Rockcliffe has been consis• tently the wettest station. N.R.C. has been the driest on the average but in two of these years the Experimental Farm was drier. It is oQvious that a considerably longer record will be necessary before any conclusion can be drawn about the normal precipitation pattern in Ottawa. The monthly total precipitation in 1955 and the normal values for the Experimental Farm are compared in the lower section of Table IV. Although the year as a whole was drier than usual, the precipitation was very irregular. In October the precipitation was two and a half times the normal. January, April, June and July each had about half the normal amount and November and December were even drier With only 33 and 28 per cent of normal, respectively. Snowfall Thirteen stations in the Ottawa region reported snow• fall throughout the winter of 1955-1956. Their monthly totals and the totals for the season are tabulated in Table V. The area of heaviest snow seems to have been centered somewhere near Rockcliffe Airport with totals for the winter of between 80 and 90 inches. Stations in the far west and south had only about 60 per cent of this total. The reports from the Experimental Farm are repeated at the foot of Table V together with the normal snowfall. Up to the end of January 1956 the snowfall was less than half the normal. In February and March it averaged 12 per cent above normal but there was no measurable snow in April. - 6 -

PART THREE : WIND Three of the stations in ottawa are equipped with cup anemometers, vUlich record the number of miles of wind in each hour, and the direction at the end of each mile. Prior to 1955 the wind speeds and directions were read from the charts of these instruments and the averages and maxima were ulti• mately published. Since January 1955 the published winds from stations that take hourly observations are compiled from the winds in these hourly observations. In other words they are wind values usually read from a dial instrument, and averaged over a few minutes at most. Each reading is essentially a spot reading instead of an average for the hour. These spot readings are recorded to sixteen compass points whereas the winds read from the charts were to only eight points. In spite of these differences it is necessary to compare the spot readings in 1955 with the averages of chart readings in previous years or else make no comparison between 1955 and the normal. For a considerable part of 1955 the anemometer at N.R.C. was not in operating condition. Even when observations were taken they appeared to be concentrated far too much in the SE and SW or in the E and Wdireotions and were frequently much too low. They are therefore not inoluded in the tables. The first section of Table VI shows the mean wind speed in miles per hour for each month and for the year. Winds were somewhat lighter than normal in mid-winter (January and February) and in the spring (April, 1my and June), but were stronger than normal in the autumn, partioularly in October. In the other three sections of Table VI two sets of values are given for Ottawa Airport in 1955. The first set in each case is to sixteen oompass points. To reduce the hours of wind from sixteen to eight directions the numbers of hours in the intermediate directions were divided between the two adjaoent primary directions in proportion to the numbers of hours already reported in those primary directions. Percentages were then calculated. The numbers of miles of wind from intermediate direc• tions were divided in the same proportions as the corresponding hours. Percentages and mean speeds were caloulated later. The percentages of hours and of miles of wind both show that Rockcliffe had more southwest winds and fewer west• northwest winds than Ottawa Airport, but the differences were rather small. At Ottawa Airport west winds were about 10 per cent more frequent than normal, and northwest and southwest winds were less frequent. - 7 -

In 1955 winds in the easterly and southerly quadrants at Rockcliffe averaged about 7 miles per hour while the same wind directions at Ottawa Airport averaged about 10 miles per hour. Northerly and westerly winds had about the same speeds at the two stations, so that the averages for all directions for the year as a whole differed by 1.5 miles per hour. Southwest and northwest winds at Ottawa Airport were somewhat lighter than normal, but for all directions the 1955 average speed was only 0.6 below normal.

CONCLUSION The type of hythergraph introduced in the report for 1954 has been used again in Fig. 2, as a graphical represen• tation of the temperature and precipitation in 1955 compared with the normals. The standard hythergraph based on reports from the Experimental Farm from 1921 to 1950 is shown with small circles. The 1955 values are at the points of the arrows. Thus ｦＧｾ｣ｨ arrow indicates by its length and direction the depaJ . ire of that month from the normal precipitation and tem• perature. The arrows pointing to the left indicate that most of the months in 1955 were relatively dry. The long arrow to the right for October indicates an exceptionally wet month. The arrows sloping downward show that January, December, and March were cold months, while the arrows for the spring and summer months show warmer than normal weather. The year as a whole was drier than the previous three years covered by these reports. The annual mean temperature was higher than in 1954 but not as warm as 1952 or 1953. No new maximum or minimum temperature records were set although July and August were quite warm and temperatures rose to within a degree of the records. The precipitation pattern for the region is still obscured by random variations although there is some evidence from three winters' snowfall of heavier snow in an area centred near Rockcliffe Airport. The wind rose in Fig. 3 emphasizes the much greater frequency of west winds and the less than normal frequencies from the northwest and southwest at Ottawa Airport in 1955. APPENDIX Weather stations within the limits of a city are generally given the name of the city followed by some other name, in brackets, to indicate the section of the city in which the station is located. In the body of this report the name "Ottawa" and the brackets have been omitted, but the full names are used in the following list. In Meteorological Division publications the name "AirportIt ia abbreviated to itA". Ottawa (N.R.C.) is at the Montreal Road Laboratories of the National Research Council. The thermometer screen and rain gauge were moved a few hundred yards in July 1954 from an elevation of 332 feet to 320 feet above sea level. The obser• vations are taken twice a day by personnel of the Division of Building Research. Rockcliffe (Airport) is only 1.1 mile northwest of the N.R.C. station but it is more than 100 feet lower. The ele• vation is only 204 feet above sea level. Weather observations are taken every hour by personnel of the R.C.A.F. Ottawa (Airport) is at Uplands at an elevation of 357 feet above sea level. Weather observations are taken every hour by personnel of the Meteorological Division of the Depart• ment of Transport. Ottawa (Experimental Farm) is at the Central Experi• mental Farm at an elevation ｯｾｏ feet. The observations are taken tv/ice a day by personnel of the Department of Agriculture. City View is at Borden's Ottawa Dairy Farm on the Merivale Road. Gatineau is at the mills of the Canadian International Paper Company at Gatineau, . Long Island is at the Long Island Locks on the Rideau Canal. The observations are taken by personnel of the Canal Services Branch of the Department of Transport. Nmnotick is at the home of Dr.N.L.Nicholson on Long Island. Orleans (Vehicle Proving Ground) is at the Proving Ground of the Vehicle Development Branch of the Department of National Defence near the Montreal Road. Ottawa (Beckwith) is at the home of Mr. W. Brideaux on Beckwith Road. Ottawa (La Salle Academy) is on Sussex Street near the Id1nt. Observations are taken by the Department of Geography. A - 2

Ottawa (Lemieux Island) is at" the Ottawa Water Purifi• cation and Pumping Station. The observations are taken by personnel of the City Water Works Department.

Shirley ｂ｡ｾ is at the Department of Transport Ionosphere Station at Shirley Bay. Ottawa (Bayview) is on the property of the City of Ottawa Engineering Department on Bayview Road. Observations are taken by the Engineering Department using their own instruments. TABLE I: EXTREME TEMPERATURES Jan. Feb. Mar. Apr. May June July Aug. Sep. Oct. Nov. Dec. Year Record Monthly , lma 54 54 80 87 95 98 101 100 102 87 75 61 102

Monthly Maxima in 1955 N.R.C. 36 39 49 77 83 90 98 98 87 75 58 36 98 Rookcliffe 36 40 53 78 85 90 100 99 88 76 59 36 100 Airport 36 39 46 76 85 91 98 98 88 76 58 36 98 Exp. Farm 35 38 48 76 83 89 99 99 88 75 57 36 99 Bayview 36 40 58 83 85 94 100 99 91 80 62 36 100 Monthly Mean Daily Maxima in 1955 N.R.C. 17.9 24.7 31.3 54.7 69.7 78.9 87.1 82.5 69.1 56.7 39.6 20.2 Rookcliffe 18.0 24.9 32.3 55.2 70.6 79.5 88.1 83.5 69.8 57.4 40.0 20.2 Airport 16.8 23.9 30.8 54.5 69.6 78.5 86.4 82.4 69.0 56.8 39.4 19.5 Exp. Farm 17.1 23.7 31.0 53.9 69.3 78.3 86.6 83.9 69.8 57.6 39.4 19.4 Bayview 20.3 26.7 34.5 58.2 70.9 80.8 88.6 86.1 71.9 59.4 41.6 22.1 Monthly Mean Daily Minima in 1955 N.R.C. 3.0 9.1 17.1 37.3 48.0 57.6 62.8 62.2 47.8 42.0 27.8 6.5 Rockcliffe 2.7 8.6 18.0 37.4 48.9 58.6 63.3 62.6 48.2 42.8 29.0 7.3 Airport 2.5 7.3 16.1 36.0 47.1 57.0 62.6 61.1 46.9 41.0 26.4 5.9 Exp. Farm 0.7 7.7 15.7 35.7 46.9 56.2 61.0 60.7 46.4 40.8 26.7 5.3 Bayview 7.2 11.9 20.2 40.5 52.1 62.4 68.8 67.2 52.2 44.7 30.7 10.4 Monthly Minima in 1955 N.R.C. -21 -20 -1 21 32 49 52 46 34 29 12 -21 -21 Rockol1ffe -24 -21 0 22 34 50 53 46 35 30 13 -21 -24 Airport -21 -18 -4 20 29 48 52 44 34 28 7 -23 -23 Exp. Farm -26 -23 -6 22 30 45 48 41 30 28 8 -24 -26 Bayview -14 -14 2 26 36 56 58 52 41 30 14 -15 -15 Record Monthly Minima -34 -35 -34 -5 21 33 38 34 24 9 -23 -38 -38

TABLE II : MEAN TEMPERATURES

ｾＮ Feb. Mar. Apr. May June July Aug. Sep. Oct. Nov. Dec. Year Monthly Mean Temperatures in 1955 N.R.C. 10.4 16.9 24.2 46.0 58.8 68.2 75.0 72.4 58.4 49.4 33.7 13.4 43.9 Rookol1ffe 10.4 16.8 25.2 46.3 59.8 69.0 75.7 73.0 59.0 50.1 34.5 13.8 44.5 Airport 9.6 15.6 23.4 45.2 58.4 67.8 74.5 71.8 58.0 48.9 32.9 ＱＲＮＷｾ 43.2 Exp. Farm 8.9 15.7 23.4 44.8 58.1 67.2 73.8 72.3 58.1 49.2 33.0 12.4 43.1 Average 9.8 16.2 24.0 45.6 58.8 68.1 74.7 72.4 58.4 49.4 33.5 13.1 43.7 Bayview 13.8 19.3 27.4 49.4 61.5 71.6 78.7 76.6 62.0 52.0 36.2 16.2 47.1 Differences from the 1955 Average N.R.C. 0.6 0.7 0.2 0.4 0 0.1 0.3 0 0 0 0.2 0.3 0.2 Rookcliffe 0.6 0.6 1.2 0.7 1.0 0.9 1.0 0.6 0.6 0.7 1.0 0.7 0.8 Airpor1; -0.2 -0.6 -0.6 -0.4 -0.4 -0.3 -0.2 -0.6 -0.4 -0.5 -0.6 -0.4 -0.4 Exp. Farm -0.9 -0.5 -0.6 -0.8 -0.7 -0.9 -0.9 -0.1 -0.3 -0.2 -0.5 -0.7 -0.6 Bayview 4.0 3.1 3.4 3.8 2.7 3.5 4.0 4.2 3.6 2.6 2.7 3.1 3.4 Experimental Farm Mean Temperatures 1955 8.9 15.7 23.4 44.8 58.1 67.2 73.8 72.3 58.1 49.2 33.0 12.4 43.1 Normal 12.0 12.7 25.2 40.5 54.2 64.1 68.6 66.4 58.4 46.1 33.0 17.4 41.6 Diffo fro NrmL-3.1 3.0 -1.8 4.3 3.9 3.1 5.2 5.9 -0.3 3.1 0.0 -5.0 1.5 TABLE III RAINFALL

Jan. Feb. Mar. ｾＮ May June July Aug. ｾＮ Oot. !!2!. Deo. Year Monthly Rainfall in 1952 N.R.C. 0 0 1.70 1.68 2.27 1.26 0.76 2.87 2.38 5.43 0.30 0 18.65 Rockcliffe . 0.05 0.21 1.85 1.97 2.87 1.75 0.77 3.61 2.61 6.14 0.62 0.06 22.51 Airport 0.06 0.25 1.31 1.64 1.64 1.94 1.21 2.70 2.14 7.18 0.64 0.28 20.99 Exp. Farm T 0.42 1.46 1.50 1.97 1.70 1.73 3.28 2.19 6.75 0.52 T 21.52 City View 0.50 0 1.42 1.35 1.87 1.53 1.32 2.49 1.92 4.63 0.53 0.11 17.67 Gatineau T .1.10 1.40 2.21 1.89 1.75 0.66 2.94 2.52 5.48 1.14 0.04 20.13 Long Island 0.90 0.43 ,1.92 1.59 2.87 2.34 0.88 3.73 1.73 7.77 0.92 0.39 25.47 Manotick 0 0.02 0.95 1.89 1.64 2.56 1.77 3.61 2.32 6.49 0.42 0.20 21.87 Orleans *T T 0.79 1.84 1.96 0.88 0.98 3.20 2.13 6.05 0.88 0 18.71 Beckwith 0.14 0.28 1.20 1.59 1.84 1.80 0.84 *2.87 2.21 4.79 0.43 0.51 18.50 La Salle 0.08 0.43 1.18 1.74 2.37 2.16 0.52 *3.27 2.55 7.11 0.62 0.04 22.07 Lemieux Is. 0 0.25 1.43 1.83 2.86 2.79 1.05 3.73 2.87 7.20 0.69 0 24.70 Shirley Bay T 0.06 0.98 1.63 1.53 2.08 1.46 2.59 2.04 7.05 0.42 0 19.84 Average 0.13 0.19 1.35 1.73 2.12 1.89 1.07 3.15 2.28 6.31 0.62 0.13 20.97 Bayview 2.15 1.68 4.03 1.95 6.48

TABLE IV : TOTAL PRECIPITATION %of Jan. Feb. Mar. Apr. May June July ｾＮ Sep. Oot. Nov. Dec. Year Aver. Monthly Total Preoipitation in 1922 N.R.C. 1.11 1.44 3.41 1.68 2.27 1.26 0.76 2.87 2.38 5.47 0.80 1.49 24.94 91 Rookcliffe 1.66 2.06 4.73 1.97 2.87 1.75 0.77 3.61 2.61 6.19 1.49 1.59 31.30 114 Airport 1.46 1.83 4.15 1.65 1.64 1.94 1.21 2.70 2.14 7.19 1.07 1.36 28.34 103 Exp. Farm· 1.48 1.94 3.67 1.50 1.97 1.70 1.73 3.28 2.19 6.75 0.97 0.84 28.02 102 City View 1.72 1.27 4.22 1.35 1.87 1.53 1.32 2.49 1.92 4.63 0.95 0.70 23.97 87 Gatineau 2.30 2.13 4.05 2.21 1.89 1.75 0.66 2.94 2.52 5.68 1.63 0.94 28.70 104 Img Island 1.90 1.68· 3.14 1.59 2.87 2.34 0.88 3.73 1.73 7.77 1.44 1.22 30.29 110 Manotick 1.28 1.67 2.99 1.89 1.64 2.56 1.77 3.61 2.32 6.50 0.73 1.28 28.24 10' Orleans *0.46 0.40 2.49 1.84 1.96 0.88 0.98 3.20 2.13 6.05 0.94 0.70 22.03 80 Beokwith 1.77 2.16 4.19 1.60 1.84 1.80 0.84 -ll2.87 2.21 4.80 1.15 1.61 26.84 91 La Salle 1.26 1.78 2.93 1.74 2.37 2.16 0.52 *3.27 2.55 7.12 1.10 1.02 27.82 10 Lemieux Is.1.15 1.93 3.69 1.83 2.86 2.79 1.05 3.73 2.87 7.20 1.19 0.79 31.08 11 ｦｨｉｲｾ Bay 1.12 1.52 3.18 1.63 1.53 2.08 1.46 2.59 2.04 7.05 1.27 0.74 26.21 91 Average 1.43 1.68 3.60 1.73 2.12 1.89 1.07 3.15 2.28 6.34 1.13 1.10 27.52 Experimental Farm Total Precipitation 1955 1.48 1.94 3.67 1.50 1.97 1.70 1.73 3.28 2.19 6.75 0.97 0.84 28.02 Normal 2.67 2.20 2.81 2.62 2.84 3.43 3.53 2.97 3.12 2.70 2.97 3.03 34.89 %of Normal 55 88 131 57 69 50 49 110 70 250 33 28 80

T Traoe Estimated '* Missilur UBLE V r SNOWFALL 1955 1956 Oot. Nov. Deo. Jan. Feb. Mar. Apr. JI18y Winter Total Monthly Snowfall in 1955-56 N.R.C. 0.4 5.0 14.9 11.2 35.6 22.9 T T 90.0 Rookol1ffe 0.5 8.7 15.3 14.0 28.7 18.5 1.3 T 87.0 Airport 0.1 4.3 10.8 11.2 20.7 21.2 1.4 0.6 70.3 Exp. Farm 0 4.5 8.4 8.2 20.3 14.9 0 T 56.3 City View T 4.2 5.9 10.5 21.0 21.5 T T 63.1 Gatineau 2.0 4.9 9.0 14.2 18.4 17.8 0 T 66.3 Long Island 0 5.2 8.3 13.0 13.3 8.3 0 0 48.1 Manotiok 0.1 3.1 10.8 13.1 14.9 12.8 1.4 0 56.2 Orleans T 0.6 1.0 10.5 26.8 24.1 0 T 69.6 Beokwith 0.1 7.2 11.0 10.9 21.0 18.4 1.5 0.5 10.6 La salle 0.1 4.8 9.8 10.4 35.1 19.3 1.2 T 81.3 Lemieux Is. 0 5.0 1.9 12.9 24.1 17.8 1.9 T 69.6 Shirley Bay T 8.5 1.4 6.4 19.1 14.5 0.9 0 56.8 Average 0.3 5.1 9.1 11.3 23.0 11.9 0.1 0.1 68.1

Experimental Farm Snowfalls 1955-56 0 4.5 8.4 8.2 20.3 14.9 0 T 56.3 Normal 0.6 1.1 18.0 18.1 16.9 14.4 4.8 T 80.5 %of Normal 0 63 41 44 120 103 0 100 10 T r Traoe

UBLE VI : WIND SPEEDS AND DIRECTIONS Jan. Feb. Mar. !E. ｾ June July Aug. Sap. Oot. Nov. Dec. Year Monthly Mean Wind Speeds Rookol1f'fe 1955 1.6 6.9 10.5 1.4 8.1 1.3 1.9 6.6 1.1 10.0 9.9 8.6 8.2 OW Airport 1955 8.1 8.6 11.1 9.5 9.1 8.2 9.2 8.2 10.0 12.1 11.0 9.5 9.1 OW Airport Normal 11.0 11.4 11.6 11.4 10.4 9.5 8.9 8.6 9.5 10.0 10.8 10.8 10.3

N NNE ｾ ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW Calm Percentage of Hours of Wind from each Direotion RO 1955 5 2 6 9 8 2 2 1 4 5 13 6 14 6 8 3 6 OW 1955 4 2 5 6 10 3 3 2 1 6 9 4 16 10 6 4 3 OW 1955 1 8 16 4 11 13 26 12 3 OW Nnol. 7 8 15 5 11 17 16 20 1 Percentage of Miles of' Wind from each Direction RC 1955 4 2 4 11 8 1 1 1 3 5 13 9 18 8 9 3 OW 1955 3 2 4 8 12 3 2 2 7 6 9 5 15 12 6 4 OW 1955 5 8 20 4 11 14 21 11 OW Nr:ml. 5 6 17 5 10 20 16 21 All Mean Wind Speed from each Direction nir, RC 1955 7.5 6.6 5.8 9.3 8.2 5.3 5.2 6.3 5.9 9.2 8.5 10.9 10.0 10.9 9.5 10.2 8.2 OW 1955 6.8 7.7 8.3 12.811.4 10.8 8.2 9.6 9.2 10.5 10.4 11.0 9.4 11.4 8.5 9.2 9.7 ow 1955 7.4 9.4 11.7 8.9 9.5 10.5 10.1 9.4 9.7 OW Nrml. 7.6 8.4 11.3 8.8 9.7 12.0 9.7 11.3 10.3 -10 0 10 20 30 40 50 60 70 80 90' I· 5 MAXIMA 1'5 1953 0 1·0 1954 0 1·0 ｾ - 0 u 1955 /),. a: 0·5 0'5 (f) 0 o 0 0 :::> z a bo a :?;- boO U 0 0 a: - 0·5 ｾ o Ch -0,5 z 0 t.6gJil ｾ g -1·0 o e° l:l 0 -1'0 e otB 6 l:l 00 -1-5 0 6 -1,5 -10 a 10 20 30 40 50 60 70 80 90 MINIMA 1-5 1953 0 1·5 hl 1954 0 0 ° 1·0 0 1955 /),. r-o 0 0 ｾ 6. 0 o 0 0 a: 0·5 0-5 0 0 OO (f) 0 CO :::> ｾ 0 ｾ DO -z 0 0 ｾ /),. B /),.0 eo 60 0 0 0 A 0 u -0,5 0 0 ＰＯＩＬＮｾＰｑ｝ 0 -0-5 · 6 oli.o 6 a:· 0 60 0 6 0 z· -1-0 6 6 A 6 -1-0 °6

-1-5 - 1'5 6

50 60 70 ROCKCLIFFE

FIGURE I DIFFERENCES OF DAILY MAXIMUM AND MINIMUM TEMPERATURES

D.B.R. INT. RPT. NO. 125 o 2 3 4 5 6 OTTAWA EXPERIMENTAL FARM

80 -_. ----- 80 AUG. ｾ ｾ )I 70 - --- 70 JIll ｾＭＭＭｹ ( .: JUNE -u, "" '\ ｾ /'""U ...... _---- • 60 IIlf SEPT. ') 60 - ｾｾ / LtJ D: II OCT. .. - ::> 50 ..J.I ...,. t- ct D: <<: l&I 40 \ 40 IL \ , ｾ .... NOV. \ l&I \ t- 30 " -- .. _-_.- 30 h.. MAR .... z / , ct / "7 l&I --,.. 20 20 // ｾ h DEC. . ,/ ... / ｾ FEB._ ｾＬＯ >- 10 . - 1---_._--_._-- -I ｾ JAN. 10 % t- Z .- 0 0 0 ｾ -10 -10

NORMAL ＱｾＵＵ ...... -20 ｾ .. -20

o I 2 3 4 5 6 MONTHLY TOTAL PRECIPITATION (INCHES)

FIGURE 2 HYTHERGRAPH COMPARING 1955 TEMPE RATURES AND PRECIPITATIONS WITH THE NORMAL VALUES.

D.B.R. INT. RPT. NO. 125 OTTAWA AIRPORT

N

W E

s

NORMAL 1955 THE CIRCLE IS AT 12 ｾＲ 0/0

FIGURE 3 WIND ROSE COMPARING THE PERCENTAGE OF

HOURS OF WIND FROM EACH DIRECTION IN

1955 WITH THE NORMAL VALUES

D.B.R. INT. RPT. NO. 125