September weather forecastBelmont, MA
September
Weather in September
The first month of the autumn, September, is also an agreeable month in Belmont, Massachusetts, with an average temperature ranging between min 56.5°F (13.6°C) and max 73°F (22.8°C).Temperature
The onset of September is marked by a minor decrease in temperature, transitioning from a warm 80.8°F (27.1°C) in August to a pleasant 73°F (22.8°C). September nights experience a consistent temperature drop to a moderate 56.5°F (13.6°C).Humidity
The average relative humidity in September is 75%.Rainfall
September is the month with the least rainfall in Belmont. Rain falls for 10.7 days and accumulates 1.3" (33mm) of precipitation.Snowfall
In Belmont, snow does not fall in June through September.Daylight
In Belmont, Massachusetts, the average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:10 am and sunset at 7:18 pm. On the last day of September, sunrise is at 6:41 am and sunset at 6:27 pm EDT.
Sunshine
In Belmont, the average sunshine in September is 8.5h.UV index
In Belmont, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for the ordinary person.Note: A maximum daily UV index of 4 during September morphs into the following directions:
Exercise caution. Those with pale skin may experience burns in less than half an hour. To guard against the harmful effects of the Sun, minimize exposure during midday. A hat with a broad brim is indispensable, filtering out up to half of UV rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Belmont, MA
- Average high temperature in September: 73°F
The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (33.4°F).
- Average low temperature in September: 56.5°F
The month with the highest average low temperature is July (64.4°F).
The coldest month (with the lowest average low temperature) is January (21.7°F).
Average pressure in September
Belmont, MA
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.07"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Belmont, MA
- Average wind speed in September: 6.5mph
The windiest month (with the highest average wind speed) is January (9.4mph).
The calmest month (with the lowest average wind speed) is August (5.9mph).
Average humidity in September
Belmont, MA
- Average humidity in September: 75%
The month with the highest relative humidity is February (78%).
The month with the lowest relative humidity is April (70%).
Average rainfall in September
Belmont, MA
- Average rainfall in September: 1.3"
The wettest month (with the highest rainfall) is December (2.95").
The driest month (with the least rainfall) is September (1.3").
Average rainfall days in September
Belmont, MA
- Average rainfall days in September: 10.7 days
The months with the highest number of rainy days are May and July (15.3 days).
The month with the least rainy days is January (7.8 days).
Average snowfall in September
Belmont, MA
- Average snowfall in September: 0"
The month with the highest snowfall is February (4.72").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Belmont, MA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (7.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Belmont, MA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 8h and 30min
The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days in September
Belmont, MA
- Average sunshine days in September: 17.4 days
The month with the most sunshine days is November (17.6 days).
The month with the least sunshine days is April (13.3 days).
Average UV index in September
Belmont, MA
- 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
Belmont, MA
- Average cloud cover in September: 36
The month with the most cloud cover is March (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in September
Belmont, MA
- 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).
