Department of Meteorology Naval Postgraduate School Monterey, California 93943 SUMMARY of the May 2021 WEATHER ON THE MONTEREY PENINSULA General: Cool, dry and windy with minimal fog sums up the weather during May 2021 on the Monterey Peninsula. Temperature: Maximum temperatures during Jan-April 2021 have been below normal for daily highs and May continued this trend. Just one daily maximum exceeded 70°F, namely 74°F on 08 May and only eight days during the month exceeded the monthly average maximum, which is 64.5°F. On three days (14, 15 and 29 May) maximum temperatures did not exceed 55°F. For the month, Upper Monterey registered an average high of 61.4°F, 3.4°F below normal and an average low of 48.0°F, 0.1°F above normal. Highest temperature at our Upper Monterey site was the above-mentioned 74°F and the lowest was 46°F on 08 and 12 May. No daily records were set or tied. In the local area, Marina reported zero days above normal for daily highs for the entire month of May. Highest readings were 86°F at Big Sur and 82°F at Carmel Valley (both on 04 May). The cool spots were Big Sur (38°F on 22 May) and Carmel Valley (39°F on 26 May). See Table of Comparative Weather Data for Stations contributing to this summary, and graphic of daily temperatures and rainfall from Upper Monterey, below. Precipitation: May’s precipitation was all of the drizzle variety. Upper Monterey recorded a total of 0.27” with measurable amounts on six days. Normal for May is 0.49” falling on four days. Rain-year totals now range from 42 to 59% of normal for local stations. Wind: Highest wind gusts recorded in the local area were 41 mph at Monterey Airport and 40 mph at Fort Ord, both on 20 May. Average winds for March were 7.7 mph at the Airport, and 11.8 mph at Fort Ord, a little stronger than average. May is has the distinction of being the month with the strongest average winds (7.5 mph at Monterey Airport). Fog: Before April 2018, with 45 years of record, a fog-day was at least one hour of visibility less than six miles. Since then, a fog-day is one or more hours with visibility less than or equal to 1/4 mile. “Mist Days” are when visibility between 1/4 and six miles is reported for at least one hour. Long term statistics for fog describe “mist” days. Mist and fog-days at Monterey Peninsula Airport and Marina fog- days for the last three months: Monterey Peninsula Airport Marina Mist Days (Normal) Fog Days Fog Days (Normal) (vis. <6 mi) (vis. <1/4 mi) (vis. <1/4 mi) March 2021 2 (7) 0 0 (3) April 2021 6 (8) 1 3 (2) May 2021 10 (8) 1 2 (2) OUTLOOK for average temperature and precipitation for Monterey, June through August 2021: NOAA’s Climate Prediction Center ENSO (El Niño / Southern Oscillation) discussion summary on 31 May 2021 reports “ENSO-neutral conditions are present. Equatorial sea surface temperatures (SSTs) are near-to-below average over the east-central and eastern Pacific Ocean. ENSO-neutral is likely to continue through the Northern Hemisphere summer (67% chance in June-August 2021).” Links to some NOAA climate pages: https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf https://www.cpc.ncep.noaa.gov/products/predictions/multi_season/13_seasonal_outlooks/color/churchill.php Seasonal outlook from NOAA’s Climate Prediction Center for June through August 2021 strongly favors above normal temperatures for the central California coast and equal chances of normal rainfall. Normal temperatures and rainfall for Monterey for the next three months: Month Rainfall (inches) # of rain days Normal Max/Min. Temps (°F) June 0.20 3 66.3 / 50.6 July 0.07 2 67.8 / 52.1 August 0.09 2 68.8 / 53.0 NOTE: Current and past Monthly Monterey Peninsula Weather Summaries, as well as historic and climate information from the National Weather Service Climate Station, are available electronically at the following website: https://met.nps.edu/~ldm/renard_wx/ Comparative Weather Data for Stations on/near the Monterey Peninsula & Salinas May 2021 Following are comparative figures from eleven local observation sites: 1) Upper Monterey, located in the western hilly section of Monterey (elevation 606 ft); 2) Monterey Peninsula Regional Airport (KMRY) site (elevation 257’), located in the flat area of eastern Monterey; 3) Naval Postgraduate School Campus (NPS), Monterey, (elevation 45’); 4) the Ft. Ord site (Ft. Ord) elevation 167’, located just north of the Marina Municipal Airport. This is the site of the Naval Postgraduate School’s wind profiler managed by the Department of Meteorology); 5) Marina, located about 2½ miles ESE of Monterey Bay (elevation 135’); 6) Carmel Valley village vicinity Ford Rd. and Lilac Ln. (elevation 475’); 7) Salinas, vicinity of W. Blanco Rd. within ½ mile of S. Main St.; 8) Carmel, located on Rio Road near east end; 9) Seaside, vicinity of Paralta and Military Aves.; 10) Pacific Grove, vicinity of Sunset and Congress Sts.; 11) Big Sur Ranger Station, Highway 1, Big Sur. Temperatures (°F) Precipitation (inches) Wind (mph) Location Rain-year Normal / Avg. Highest Avg. Lowest This month (01 Jul – % of normal Max. Gust / Average Max. Min. May 31 May date(s) Upper 18.98* / ( 24 ) Monterey 61.4 74 48.0 46 0.27 b 11.15 59% 20th 1.9 Monterey % ( 41 ) Airport 65.5 73 51.5 47 0.00 b 7.57 --- 20th 7.7 NPS 15.27# / ( 30 ) 64.1 72 48.3 42 0.04 b 7.97 52% 19th 4.0 Ft. Ord ( 40 ) 61.0 68 46.5 41 0.10 b 8.39 --- 20th 11.8 Marina 15.35 & / ( 34 ) 61.7 68 48.3 42 0.11 a 8.16 53% 20th --- Carmel Valley 71.6 82 44.7 39 0.03 10.75 --- --- --- Salinas 13.56 ∆ / 67.0 78 50.7 45 0.00 5.75 42% --- --- Carmel 58.7 74 46.8 41 0.06 8.92 --- --- --- Seaside 60.1 70 48.3 42 0.07 6.84 --- --- --- Pacific Grove 59.1 65 48.7 45 0.09 9.10 --- --- --- Big Sur 70.5 86 45.2 38 0.00 17.56 --- --- --- FOOTNOTES: Observations for precipitation: a = 5 or 6 PM, b = midnight local time * = NWSCS/Upper Monterey 66-year average # = 51-year average, & = 37-year average, ∆= 24-year average % = Monterey Peninsula Regional Airport replaced NWSFO on 01 April 2019 Winds from Monterey Peninsula Airport (based on a 24-h period, ending at local midnight) .