September weather forecastWindham, NH
September
Weather in September
September signifies the arrival of the late-summer to early-fall transitory phase. It heralds the gradual reduction of heat, though the weather still remains comfortably warm for the most part. In contrast to the preceding months, September offers no precipitation, marking the first month devoid of rainfall. Subsequently, the winds ramp up a bit, flirting with the approaching autumn. Meanwhile, the humidity scales down a notch, enhancing the overall ease of the season.Temperature
A mild shift in the average high-temperature occurs in September, reducing from a moderately hot 79.9°F (26.6°C) in August to an agreeable 72.3°F (22.4°C). During September, an average low-temperature of 55.8°F (13.2°C) is observed.Humidity
In Windham, the average relative humidity in September is 76%.Rainfall
The month with the least rainfall is September, when the rain falls for 10.6 days and typically collects 1.3" (33mm) of precipitation.Snowfall
In Windham, snow does not fall in June through September.Daylight
The average length of the day in September is 12h and 29min.On the first day of the month, sunrise is at 6:10 am and sunset at 7:19 pm. On the last day of September, sunrise is at 6:42 am and sunset at 6:27 pm EDT.
Sunshine
The average sunshine in September is 8.6h.UV index
The average daily maximum UV index in September in Windham is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for average individuals.Note: A maximum high daily UV index of 4 during September translates into the following directions:
Be careful. Light complexion individuals might get burns in fewer than 30 minutes. The mid-day Sun emits the most powerful UV radiation, so seek shade and minimize exposure. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Windham, NH
- Average high temperature in September: 72.3°F
The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (32.2°F).
- Average low temperature in September: 55.8°F
The month with the highest average low temperature is July (63°F).
The coldest month (with the lowest average low temperature) is January (20.3°F).
Average pressure in September
Windham, NH
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.06"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Windham, NH
- Average wind speed in September: 6mph
The windiest month (with the highest average wind speed) is January (9.2mph).
The calmest month (with the lowest average wind speed) is August (5.5mph).
Average humidity in September
Windham, NH
- Average humidity in September: 76%
The month with the highest relative humidity is February (79%).
The month with the lowest relative humidity is April (71%).
Average rainfall in September
Windham, NH
- Average rainfall in September: 1.3"
The wettest month (with the highest rainfall) is December (2.87").
The driest month (with the least rainfall) is September (1.3").
Average rainfall days in September
Windham, NH
- Average rainfall days in September: 10.6 days
The month with the highest number of rainy days is May (15.9 days).
The months with the least rainy days are January and February (7.6 days).
Average snowfall in September
Windham, NH
- Average snowfall in September: 0"
The month with the highest snowfall is February (5.87").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Windham, NH
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (8.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Windham, NH
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 8h and 36min
The month with the most sunshine is August (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days in September
Windham, NH
- Average sunshine days in September: 17.9 days
The month with the most sunshine days is September (17.9 days).
The month with the least sunshine days is May (13.5 days).
Average UV index in September
Windham, NH
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Windham, NH
- Average cloud cover in September: 35
The month with the most cloud cover is March (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 31).
Average visibility in September
Windham, NH
- Average visibility in September: 6mi
The months with the highest visibility are January, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is February (5mi).
