August 2024 Summary – Drier and Sunnier Than Average

Blue Hill Observatory August 2024 Summary:

August temperature was near average with less rainfall and more sunshine than average. The approximated 24-hour mean temperature for the month of 69.7 deg F was 1.4 degrees warmer than the 1891-2020 130-year average for August, and it was 0.6 degrees cooler than the 1991-2020 30-year average. The average maximum temperature of 79.9 deg F was 0.3 degrees cooler than the 30-year normal, and the average minimum temperature of 61.6 deg F was 1.0 degrees cooler than the 30-year normal. The month got off to a very warm start with the second three-day heat wave of the summer on the 1st-3rd, and the highest temperature for August reached 94F on the 2nd. The lowest temperature was 51F on the 21st. August mean water vapor pressure, which is an absolute measure of water vapor in the air, was 19.5 mb, which corresponds to a mean dew point of 63F. The long-term mean water vapor pressure for August is 18.4 mb, which equals a mean dew point of 61F. The total precipitation was 2.96 inches, which was 0.95 inches less than the 30-year normal. The greatest amount in 24 hours was 0.82 inches on the 9th-10th, which was most of the storm total of 0.85 inches observed during the passage of former Hurricane Debby as a post-tropical cyclone well inland to the west. There were four thunderstorm days during August, which was average, and the total for the year through August climbed to nineteen. The mean wind speed was 9.2 mph, which is a new record low average wind speed for August that also ties the record for any month of the year. The prevailing wind direction was from the west. The highest wind gust was 50 mph from the south-southwest on the 9th during the passage of post-tropical cyclone Debby. August sunshine was above average with 255.7 hours of bright sunshine, or 62 percent of possible, which was three percent more than the long-term average for the month.

BHO Lowest Monthly Mean Wind Speed, mph (1885-2024):

1) 9.2 in June 2023
   9.2 in August 2024
3) 9.3 in July 2023
4) 9.5 in August 1996
   9.5 in August 2008
   9.5 in August 2021
7) 9.6 in July 2019
   9.6 in October 2022

BHO Lowest August Mean Wind Speed, mph (1885-2024):

1) 9.2 in 2024
2) 9.5 in 1996
   9.5 in 2008
   9.5 in 2021
5) 9.8 in 2019
6) 10.0 in 1899
   10.0 in 2009
   10.0 in 2022

Mike Iacono
Chief Scientist
Blue Hill Observatory