Chapter 2 Weather and Climate Ken Cook and Ian Findlay

Weardale weather © Ian Turner

Introduction

The are unique in England as the only significant upland area not close to the sea, with climatic implications. The high hills (up to 740 m AOD at the source of the Wear) maintain wet and cool conditions in the upper Dale and cast a rain shadow, creating drier conditions to the east. Yet gales from the north and east can bring heavy rain, and snow in the winter. Neighbouring Teesdale is unique in having more data and long-term weather stations than any other UK upland area. A continuous temperature record is available from 1931 (Holden & Adamson, 2001). Gordon Manley of began recording at Moor House at 550 m in the 1950s. Some parallels may be drawn from these records for Weardale, where local records go back to 1970.

41 What are conditions like? Gordon Manley summarised the climate at high altitudes in the Pennines as follows; ‘We therefore form a conception of excessively windy and pervasively wet autumn, a very variable and stormy winter with long spells of snow cover, high humidity and extremely bitter wind, alternating with brief periods of rain and thaw. April has a mean temperature little above the freezing point and sunny days in May are offset by cold polar air, while the short and cloudy summer is not quite warm enough for the growth of trees. Throughout the year, indeed, the summers are frequently covered in cloud’. The climate above 750 m is tundra/sub-polar oceanic. Cool, wet conditions have dictated a range of vegetation and associated fauna in the upper Dale. Blanket bog, rare in a global context, is common above 500 m on limestone and other rock types. Climatic conditions allow some plant growth but only partial decomposition of dead material, forming peat to a depth of around 2 m. At altitudes above 350 m, the growing season is very short, even with ‘the best weather’, with implications for wildlife and hill farmers. And extreme climatic events are a characteristic of uplands weather, including severe winters with late-winter and heavy snowfall or prolonged snow cover. Weather has dictated the rate of farming practice, particularly up to 1960 when the horse Temperature range, was relied upon rather than the tractor. Bollihope © Ian Turner Records 1981 to 2010 The following data show 30-year means from three weather recording stations moving down the Dale from west to east and the graph shows how snowy it has been in Copley. Below 7˚C vegetation does not grow, the invertebrate prey of nesting birds may be hard to find – inactive, trapped in frozen mud or buried in snow.

Temperature means and Precipitation (pptn), 1981­2010 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Westgate max (˚C) 4.7 5.1 7.3 10.3 13.6 16.1 18.3 17.7 15.3 11.5 7.8 5.2 11.1 335 AOD min (˚C) –0.2 –0.3 1.1 2.5 4.9 7.9 10.1 9.8 7.8 5.4 2.5 0.2 4.3 pptn (mm) 110 85 87 74 62 65 62 71 83 105 120 115 1,038 Stanhope max (˚C) 6.1 6.9 9.6 13.1 16.6 19.2 21.3 20.6 17.9 13.6 9.3 6.5 13.4 215 AOD min (˚C) 1.1 1.2 2.8 4.3 6.9 9.9 12.1 11.6 9.5 6.8 3.8 1.5 6.0 daily 3.6 4.1 6.2 8.7 11.8 14.5 16.7 16.9 13.7 10.2 6.5 4.0 9.7 pptn (mm) 77 62 58 66 50 60 62 61 81 94 99 98 866 Copley max (˚C) 5.0 5.3 7.6 10.7 14.2 17.0 19.2 18.4 15.7 11.6 7.9 5.9 11.5 253 AOD min (˚C) –0.1 –0.1 1.3 2.6 5.1 7.9 10.3 10.1 8.4 5.6 2.5 0.5 4.5 daily 2.4 2.6 4.4 6.7 9.6 12.4 14.7 14.2 11.9 8.6 5.2 2.9 8.0

pptn (mm) 75 70 66 64 52 64 71 70 65 95 84 88 864

The average number of snow falling days throughout the year. Based on 1981-2010 averages, source .

Data for table and chart provided by Ken Cook, source Met Office.

43 Weather data at Copley, 2001­2010

Temperature ˚C Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Mean daily max. 5.4 5.9 8.8 11.5 14.5 17.6 19.5 18.8 16.3 12.1 8.3 5.1 12.0 Mean daily min. 0.3 –0.1 0.9 2.9 5.3 8.3 10.3 10.5 8.6 5.8 2.7 –0.1 4.6 Mean temperature 2.9 2.9 4.5 7.2 9.9 12.9 14.9 14.7 12.5 8.9 5.6 2.5 8.3 Highest maximum 12.5 13.9 15.9 22.6 27.7 26.6 30.0 28.4 24.7 20.0 16.2 14.4 30.0 Year 2003 2008 2009 2007 2010 2005 2006 2003 2006 2007 2007 2003 17/7/06 Lowest minimum –9.7 –10.7 –12.8 –4.9 –4.2 0.6 3.6 3.3 1.2 –2.4 –9.4 –10.4 –12.8 Year 2002 2008 2001 2003 2010 2005 2002 2005 2007 2008 2010 2010 3/3/01 Lowest grass min. –17.2 –15.9 –18.5 –10.1 –10.0 –4.1 –3.3 –0.9 –2.9 –8.9 –16.3 –18.6 –18.6 Year 2002 2008 2001 2002 2010 2005 2006 2005 2003 2008 2010 2005 29/12/05 Highest minimum 8.4 8.0 8.5 11.3 12.1 15.6 15.8 17.5 14.5 12.1 12.0 8.1 17.5 Year 2004 2004 2006 2007 2003 2005 2006 2004 2003 2005 2007 2005 9/8/04 Lowest maximum –1.6 –0.7 –0.7 3.9 6.0 6.4 11.1 12.5 8.5 3.8 –2.5 –2.9 –2.9 Year 2010 2003 2006 2008 2010 2009 2004 2007 2007 2008 2010 2010 17/12/10 Air frosts 15.9 15.8 12.2 6.0 1.3 0.0 0.0 0.0 0.0 1.6 6.6 16.0 75.4 Concrete slab frosts 19.2 17.9 13.8 6.9 1.2 0.0 0.0 0.0 0.1 2.9 10.3 18.6 90.9 Earth temperature Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 30cm depth (am) 4.0 3.9 4.9 8.0 11.3 14.3 16.0 16.2 14.3 11.0 7.7 4.9 9.7 100cm depth (am) 5.3 4.9 5.2 7.3 9.9 12.6 14.3 15.0 14.0 11.7 9.1 6.5 9.7

Precipitation mm Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Monthly mean 73.4 70.5 57.3 52.0 46.5 73.2 94.4 80.0 65.5 89.5 80.2 80.3 862.8 rain days =>0.2mm 21.5 15.3 15.9 14.5 15.2 13.7 17.0 16.4 13.9 19.1 19.4 18.5 200.4 wet days =>1.0mm 14.1 11.4 10.6 9.7 10.2 9.8 11.0 11.0 8.9 13.9 13.1 13.1 136.3 Days =>5.0mm 4.3 4.9 3.4 3.8 2.6 4.5 4.9 4.1 4.0 6.3 5.0 6.1 53.9 Wettest day 30.1 31.0 27.7 25.4 29.2 30.2 87.9 53.1 56.5 30.7 28.4 33.2 87.9 Year 2005 2009 2005 2009 2006 2007 2009 2004 2008 2002 2009 2002 01/07/09 Wettest month 133.9 151.3 113.2 106.4 120.7 187.6 267.9 250.4 119.3 154.2 184.7 142.9 1,008.1 Year 2008 2002 2006 2001 2006 2007 2009 2004 2008 2002 2009 2002 Driest month 14.0 28.0 26.6 13.4 18.4 21.1 19.7 10.3 20.1 23.6 14.6 42.1 590.7 Year 2006 2008 2009 2007 2004 2006 2006 2003 2009 2007 2004 2010

44 Sunshine hours Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Monthly mean 71.4 94.5 135.6 151.1 183.0 158.4 162.1 145.7 130.6 100.1 82.8 72.3 1,487.6 Daily mean 2.30 3.37 4.37 5.04 5.90 5.28 5.23 4.70 4.35 3.23 2.76 2.33 4.07 Days nil sunshine 7.7 4.9 4.3 2.4 2.1 2.6 2.0 1.5 2.8 6.0 5.4 9.1 50.8 Sunniest day 8.1 9.8 12.5 13.8 16.4 16.2 16.1 13.9 12.7 10.7 8.5 7.0 16.4 Year 2006 2004 2009 2009 2009 2010 2006 2003 2002 2007 2006 2001 30/5/09 Sunniest month 101.3 132.2 200.2 204.2 254.5 211.6 305.6 185.1 163.4 136.1 127.4 89.4 1,707.0 Year 2007 2008 2003 2007 2001 2010 2006 2007 2005 2003 2005 2006 Dullest month 61.8 66.7 75.4 92.9 125.9 103.5 126.5 87.4 83.9 40.0 55.0 35.4 1,272.2 Year 2002 2010 2005 2004 2002 2007 2010 2008 2008 2005 2002 2002

Wind KT Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Monthly mean, 10m 12.5 11.0 10.6 9.0 8.7 7.7 7.6 7.8 8.6 9.0 10.9 10.8 9.5 Highest gust 77 69 66 51 57 62 54 47 51 62 62 65 77 Year 2005 2008 2007 2003 2002 2008 2006 2005 2005 2004 2006 2006 8/1/05 Gale days 2.6 1.4 1.2 0.0 0.1 0.1 0.0 0.0 0.0 0.6 1.4 1.4 8.8

Days with ... Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Snow/sleet falling 12.6 12.2 9.0 4.5 0.5 0.0 0.0 0.0 0.0 1.0 5.1 11.4 56.3 Snow lying >50%, am 9.1 7.9 5.2 0.4 0.0 0.0 0.0 0.0 0.0 0.0 1.7 6.8 31.1 greatest depth (cm) 44 27 25 10 0 0 0 0 0 0 30 40 44 Year 2010 2001 2001 2008 2010 2010 6/1/10 Hail <5mm 1.9 2.9 2.2 1.8 1.2 0.3 0.3 0.0 0.0 0.5 0.5 1.3 12.9 Hail =>5mm 0.0 0.1 0.0 0.4 0.4 0.2 0.1 0.2 0.0 0.0 0.0 0.0 1.4 Thunder heard 0.0 0.0 0.2 0.7 0.8 1.8 2.3 1.6 0.2 0.5 0.1 0.0 8.2 Fog, am 3.2 3.1 2.2 1.7 0.7 1.2 0.5 1.1 2.1 3.7 3.2 4.0 26.7

Data recorded at Copley Meterological Weather Station by, and used with permission of, Ken Cook. The figures on these tables must be read with the understanding that they reflect the weather patterns only in Copley, at an altitude of 253m A OD (Above Ordnance Datum, equivalent to above mean sea level). Weather patterns in the large areas of the uplands varying in height from 350m to 700m in upper parts of Weardale will be harsher. At these altitudes the growing season is very short. The facts and figures highlight that in any given year farming/wildlife has to cope with complex weather conditions.

45 Some extreme weather events

1878 –18.3°C at Gainford, coldest Christmas Day in the UK 5 Jan 1941 –21.1°C at Houghall Mar 1947 211cm level snow at Forest in Teesdale Winter 1963 upper dale below freezing for 3 months Jan 1968 134mph gusts on , 100mph for one hour 2 Feb 1986 0°C throughout the dale above 200m 16 Jul 2006 25.6°C (27.5˚C/1.9˚C) daily range at Copley Lead Mill 1 Jul 2009 87.9mm rainfall in thunderstorm at Copley 22 May 2010 27.7°C max at Copley, highest in UK so far for that month 2 Dec 2010 –20.0°C at Ravensworth (first time –20°C in England since Jan 1987)

Many more extreme weather events have been recorded in the North Pennines and residents in Weardale have suffered their fair share.

Weardale snow © Ian Turner

46 What is happening in the Dale now?

The detailed records at Copley, at the bottom of the Dale, indicate changes that may well be reflected elsewhere to varying degrees. Since 2000 the weather pattern has altered, with extremes of rainfall, sunshine and strong winds. Winters have had less snowfall and periods of snow cover measured in weeks, not months. It will be interesting to see what the 2010 to 2020 data will show and the overall trends for the past 20 years. More change, more extremes — in weather and locations? As chapter 4 describes, climate change is not new, but the speed of recent change and potential scale of its impact on wildlife and implications for the Dale’s farming community are cause for serious concern. Wet open winters with a higher rainfall delay ground warming in the spring affecting invertebrate eggs and overwintering pupae, including those of moths, that are the food for early nesting wader chicks. Slow growth of vegetation delays suckler cows and their calves being turned out into pastures by two or three weeks, at extra feed cost to the farmer. Warm early months stimulate plant growth and premature return of birds from their overwintering grounds, but sudden cold spells can then spell disaster. Extreme weather shifts are not good. A surge of bracken growth on the lower fells cannot be managed by chemical treatment and is associated with less snow cover and fewer frost days. Rushes have spread extensively in pastures and wet areas due to lower cattle grazing, not helped by open winters and high rainfall. Rabbit populations are higher so grazing is more intense; previously hard winters kept rabbits under control. Fewer sheep graze the uplands allowing Blue Moorgrass to dominate areas to the detriment of

47 rare plants. A similar increase in Bog Asphodel puts sheep and lambs at risk from its high toxicity. Heavy and sudden rainfall damages roads and drains, causing

disruption, delays and expense. Reducing climate change is a key factor in conserving the wildlife and traditional farming in Weardale. Tackling climate change is a world-wide priority that may impact in Weardale in many ways. A large scale planting of trees in upland areas, to mitigate the amount of atmospheric carbon dioxide, is advocated by some, but is further restoration of peatland to sequester carbon a better option?

Further information

All data in this chapter are used with permission of Ken Cook who runs the Meterological Weather Station at

Above Wolsingham Copley and Copley Mill. © Ian Turner More information is available at the Royal Meterological Society website RmetS. Holden, J and Adamson, J K, 2001, Gordon Manley and the North Pennines, Journal of Meteorology 26, 329-333. Holden, J and Adamson, J K, 2002, The Moor House long-term upland temperature record: new evidence of recent warming, Weather, 57, 119-127. Manley, G (1942), Meteorological observations on Dun Fell, a mountain station in northern England, Quarterly Journal of the Royal Meteorological Society, 68, 151-165. Manley, G, 1980, The Northern Pennines revisited: Moor House, 1932- 78, Meteorological Magazine, 109, 281-292. Wheeler, Dennis, University of Sunderland, 2013, Regional weather and climates of the British Isles – Part 4: North East England and Yorkshire, Weather, 68, No.7, July, 184-190.

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