October 2025 Summary – Warmer and Wetter Than Average

Blue Hill Observatory October 2025 Summary: 

October 2025 was warmer than normal with more precipitation and more sunshine than average. The approximated 24-hour mean temperature for the month of 53.6 deg F was 2.3 degrees warmer than the 1891-2020 130-year average for October, and it was 1.4 degrees warmer than the 1991-2020 30-year average. The average maximum temperature of 62.2 deg F was 1.2 degrees warmer than the 30-year normal, and the average minimum temperature of 46.2 deg F was 2.2 degrees warmer than the 30-year normal. The warmest period occurred during the first week of the month, which included three consecutive days that exceeded 80F. The highest temperature for the month was 84F on the 5th, and the lowest temperature was 34F on the 27th. October mean water vapor pressure, which is an absolute measure of water vapor in the air, was 10.9 mb, which corresponded to a mean dew point of about 47F. This amount was above the long-term mean water vapor pressure for October of 10.1 mb, which equals a mean dew point of about 45F. The total precipitation was 6.49 inches, which was 1.00 inches more than the 30-year normal. There were two significant storms during the month including a coastal storm that brought 3.54 inches of rain on the 12th-14th and a peak wind gust to 51 mph from the east-northeast on the 13th. The greatest rainfall in 24 hours was 2.69 inches on the 12th-13th. The second was a strong inland storm that brought a tropical feed of moisture, strong winds, and 0.96 inches of rainfall on the 29th-31st while a weakening Hurricane Melissa passed far out at sea. There was one thunderstorm day during the month, which was average, and the total for the year through October increased to 22, which was also average. The lowest sea-level pressure was 29.11 inches on the 31st, and the highest sea-level pressure was 30.55 inches on the 10th. The mean wind speed was 11.9 mph, and the prevailing wind direction was from the north-northwest. The highest wind gust was 60 mph from the west during the departure of the strong storm on the 31st. October sunshine was above average with 197.1 hours of bright sunshine, or 60 percent of possible, which was five percent more than the long-term average for the month.

Mike Iacono
Chief Scientist
Blue Hill Observatory