September 2022 Summary – Slightly Wetter Than Average

Blue Hill Observatory September 2022 Summary: 

September temperature and sunshine were close to average, and it was the first month since February with more precipitation than average. The approximated 24-hour mean temperature for the month of 62.5 deg F was 1.0 degrees warmer than the 1891-2020 130-year average for September, but it was 0.6 degrees cooler than the 1991-2020 30-year average. The average maximum temperature of 71.8 deg F was 0.9 degrees cooler than the 30-year normal, and the average minimum temperature of 54.4 deg F was 1.2 degrees cooler than the 30-year normal. There were no temperature extremes during September. The highest temperature for the month was 86F on the 4th, and the lowest temperature was 42F on the 24th. The total precipitation was 4.41 inches, which was slightly more than average with 0.35 inches more than the 30-year normal. The greatest rainfall in 24 hours was 1.72 inches on the 5th-6th, which was part of 2.40 inches that fell over those two calendar days. This storm was the heaviest rainfall event of the year to date at the Observatory, and it brought 8-12 inches of rain to parts of Rhode Island to the south. There were two thunderstorm days during September, which was average, and the annual total is up to 17, which is four less than average through September. The mean wind speed for the month was 10.3 mph, which was the second lowest on record for September, and the prevailing wind direction was from the west. The highest wind gust was 48 mph from the north-northwest on the 23rd. September sunshine was close to average with 200.5 hours of bright sunshine, or 56 percent of possible, which was one percent less than the long-term average for September.

BHO Lowest September Mean Wind Speed (1885-2022):

1) 10.1 in 2018
2) 10.3 in 2022
3) 10.5 in 2014
4) 10.6 in 2013
5) 10.7 in 2011
   10.7 in 2015
7) 10.8 in 2017

Mike Iacono
Chief Scientist
Blue Hill Observatory