May 2022 Summary – Warmer and Drier Than Average

Blue Hill Observatory May 2022 Summary: 

May was warmer than average and the third straight month with much less rainfall than expected. The 24-hour adjusted mean temperature for the month of 58.9 deg F was 3.4 degrees warmer than the 1891-2020 130-year average for May, and it was 2.2 degrees warmer than the 1991-2020 30-year average. The average maximum temperature of 70.0 deg F was 3.6 degrees warmer than the 130-year mean. The average minimum temperature of 50.5 deg F was 4.0 degrees warmer than the 130-year mean and tied for the fourth warmest on record. The highest temperature observed all month was 93F on the 22nd, which tied the record for the date previously set in 1911. The low temperature on the 22nd of 68F surpassed the record for the date of 67F set in 1992. A daily record high temperature was also tied on the 14th with 85F, matching the reading previously set in 1961. The lowest temperature during May was 39F on the 9th. The total precipitation was 1.30 inches, which was about two and a half inches less than the 130-year average and the 1991-2020 30-year mean. The month was the tenth driest May on record. The greatest rainfall in 24 hours was 0.44 inches on the 2nd-3rd. There were four thunderstorm days during May, which was one more than average for the month. There was no frozen precipitation in May, and the final snowfall for the 2021-2022 season was 70.7 inches, which was nearly nine inches more than the long-term average and about two inches more than the 30-year average. The mean wind speed for the month was 11.4 mph, and the prevailing wind direction was from the south-southwest. The highest wind gust was 48 mph from the east-northeast on the 7th. May sunshine was above average with 248.5 hours, or 57 percent of the possible bright sunshine, which was five percent more than the long-term average.

BHO Warmest May Average Minimum Temperature, degF (1885-2022):

1) 52.5 in 2012
2) 51.3 in 2018
3) 51.2 in 1944
4) 50.5 in 1979
   50.5 in 2022
6) 50.4 in 2010
7) 50.3 in 1991

BHO Lowest May Precipitation, inches (1885-2022):

1) 0.50 in 1944
2) 0.62 in 1964
3) 0.89 in 1911
4) 1.11 in 1899
5) 1.20 in 1959
6) 1.21 in 1955
7) 1.23 in 1993
8) 1.24 in 1923
9) 1.28 in 1903
10) 1.30 in 2022

Blue Hill Observatory Spring (March – May) 2022 Summary:

Spring was much warmer and much drier than average. The 24-hour adjusted mean temperature for the season of 48.4 deg F was 3.5 degrees warmer than the 1891-2020 130-year average for spring, and it was 2.0 degrees warmer than the 1991-2020 30-year average. Spring tied as the fifth warmest on record. The average maximum temperature of 59.0 deg F was 4.0 degrees warmer than the 130-year mean, which tied as the sixth warmest on record. The average minimum temperature of 39.6 deg F was 2.9 degrees warmer than the 130-year mean, and it was the eighth warmest on record. The temperature extremes during spring ranged from a low of 10F on March 4th to a high of 93F on May 22nd. The total seasonal precipitation for spring was 7.44 inches, which was five inches less than the 130-year average and nearly seven inches less than the 1991-2020 30-year mean. The season was the tenth driest spring on record. Each month was drier than average, and part of the area had reached moderate drought status by the end of May. There were five thunderstorm days during spring, which was average for the season. Total spring snowfall was just 4.1 inches, all of which fell during March, and this amount was about a foot less than average. The mean wind speed for the season was 12.4 mph, which was the third lowest on record, and the prevailing wind direction was from the west-northwest. The highest wind gust was 59 mph from the west-northwest on March 7th. Each month was sunnier than average, and spring sunshine was above average with 55 percent of the possible bright sunshine, which was five percent more than the long-term average.

BHO Warmest Spring (Mar-May) 24-Hour Corrected Mean Temperature, deg F (1885-2022):

1) 51.3 in 2010
2) 50.9 in 2012
3) 49.4 in 1991
4) 49.0 in 1977
5) 48.4 in 1998 
   48.4 in 2022
7) 48.2 in 1976

BHO Warmest Spring (Mar-May) Average Maximum Temperature, deg F (1885-2022):

1) 61.4 in 2010
2) 61.1 in 2012
3) 60.5 in 1991
4) 60.3 in 1977
5) 59.6 in 1945
6) 59.0 in 1976
   59.0 in 2022
8) 58.8 in 1903

BHO Warmest Spring (Mar-May) Average Minimum Temperature, deg F (1885-2022):

1) 42.6 in 2012
2) 42.4 in 2010
3) 40.5 in 1945
4) 40.4 in 1998
5) 39.9 in 1973
6) 39.8 in 1991
7) 39.7 in 1979
8) 39.6 in 2022

BHO Lowest Spring (Mar-May) Precipitation, inches (1885-2022):

1) 4.51 in 1915
2) 5.39 in 1981
3) 6.01 in 1910
4) 6.18 in 1995
5) 6.41 in 1965
6) 6.50 in 1966
7) 6.68 in 1927
8) 6.81 in 1986
9) 7.02 in 1911
10) 7.44 in 2022

BHO Lowest Spring (Mar-May) Mean Wind Speed, mph (1885-2022):

1) 12.0 in 2012
2) 12.3 in 2016
3) 12.4 in 2022
4) 12.6 in 1995
    12.6 in 2018

Mike Iacono
Chief Scientist
Blue Hill Observatory