March 2025 Summary – Warmer Than Average

Blue Hill Observatory March 2025 Summary:

March was much warmer than normal, with average precipitation and record low snowfall. The approximated 24-hour mean temperature for the month of 40.2 deg F was 5.7 degrees warmer than the 1891-2020 130-year average for March, and it was 4.4 degrees warmer than the 1991-2020 30-year average. The month tied as the twelfth warmest March on record. The average maximum temperature of 50.1 deg F was 6.0 degrees warmer than the 30-year normal, and it was the ninth warmest on record. The average minimum temperature of 31.1 deg F was 4.2 degrees warmer than the 30-year normal. After a very cold start on the 2nd and 3rd, warmth dominated the month and only eight days averaged at or below normal. The warmest temperature was 67F on the 16th, and the coldest temperature was 8F on the 3rd. The mean water vapor pressure, which is an absolute measure of water vapor in the air, was 6.1 mb, which corresponds to a mean dew point of 32F, and this value was above the average of 4.8 mb, or 27F, for the month. The total precipitation was 5.06 inches, which was 0.46 inches below the 30-year normal. Nearly half of the monthly total occurred during the largest storm of the month on the 16th-17th, which brought rain, warm temperatures, strong winds, and a storm total of 2.17 inches, which was also the greatest amount in 24 hours. Another notable storm on the 5th-6th brought 1.18 inches of rain, which ended as a trace of snow, and very strong southerly winds. The snowfall total for the month was only a trace, on four days, which was 15.0 inches less than the 30-year normal, and this amount of snow tied as the lowest on record for March. It was only the third time on record that only a trace of snow was measured in March, matching 1921 and 2024. There were no thunderstorm days during the month. The lowest sea-level pressure during March was 988.0 mb, or 29.18 inches, on the 6th. The mean wind speed was 14.0 mph, and the prevailing wind direction was from the west-northwest. The highest wind gust was 69 mph from the south during the storm on the 6th. March sunshine was above average with 185.4 hours of bright sunshine, or 52 percent of possible, which was three percent more than the long-term average for the month.  

BHO Warmest March Average Maximum Temperature, deg F (1885-2025):

1) 55.9 in 1946
2) 54.4 in 1945
3) 53.6 in 2012
4) 52.6 in 1921
5) 52.3 in 1903
6) 50.9 in 2000
7) 50.2 in 1977
50.2 in 2021
9) 50.1 in 2025
10) 49.8 in 2020

BHO Lowest March Snowfall, inches (1891-2025):

1) Trace in 1921
   Trace in 2024
   Trace in 2025
4) 0.1 in 1979
   0.1 in 2006
6) 0.2 in 1903
   0.2 in 2021
8) 0.3 in 1930
9) 0.4 in 1974

Mike Iacono
Chief Scientist
Blue Hill Observatory