September weather forecastCharlton, MA
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Charlton, Massachusetts, with an average temperature varying between 72°F (22.2°C) and 53.8°F (12.1°C).Temperature
September marks a gentle change in average high-temperature, declining from August's moderately hot 79.5°F (26.4°C) to an agreeable 72°F (22.2°C). Throughout the month of September, Charlton sees a steady low-temperature average of 53.8°F (12.1°C).Humidity
In September, the average relative humidity is 79%.Rainfall
September is the month with the least rainfall. Rain falls for 12.4 days and accumulates 1.81" (46mm) of precipitation.Snowfall
In Charlton, snow does not fall in June through September.Daylight
In Charlton, the average length of the day in September is 12h and 28min.On the first day of September, sunrise is at 6:14 am and sunset at 7:21 pm. On the last day of the month, sunrise is at 6:44 am and sunset at 6:30 pm EDT.
Sunshine
In Charlton, the average sunshine in September is 8h.UV index
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 average individuals.Note: An average UV index of 4 in September transforms into this advice:
Heed the precautions - It is counselled to guard against solar damage. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. Stay sun-safe with clothing that is both closely woven and worn loosely.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Charlton, MA
- Average high temperature in September: 72°F
The warmest month (with the highest average high temperature) is July (81.3°F).
The month with the lowest average high temperature is January (31.5°F).
- Average low temperature in September: 53.8°F
The month with the highest average low temperature is July (61.7°F).
The coldest month (with the lowest average low temperature) is January (19.6°F).
Average pressure in September
Charlton, MA
- Average pressure in September: 30.06"Hg
The month with the highest atmospheric pressure is November (30.08"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Charlton, MA
- Average wind speed in September: 6.2mph
The windiest month (with the highest average wind speed) is January (9mph).
The calmest month (with the lowest average wind speed) is August (5.7mph).
Average humidity in September
Charlton, MA
- Average humidity in September: 79%
The month with the highest relative humidity is February (81%).
The month with the lowest relative humidity is April (72%).
Average rainfall in September
Charlton, MA
- Average rainfall in September: 1.81"
The wettest month (with the highest rainfall) is December (3.11").
The driest month (with the least rainfall) is September (1.81").
Average rainfall days in September
Charlton, MA
- Average rainfall days in September: 12.4 days
The month with the highest number of rainy days is July (16.3 days).
The months with the least rainy days are January and February (7.8 days).
Average snowfall in September
Charlton, MA
- Average snowfall in September: 0"
The months with the highest snowfall are February and March (5.08").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Charlton, MA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is March (9.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Charlton, 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 12min).
- Average sunshine in September: 8h and 0min
The month with the most sunshine is August (Average sunshine: 10h and 0min).
The month with the least sunshine is February (Average sunshine: 4h and 30min).
Average sunshine days in September
Charlton, MA
- Average sunshine days in September: 15.9 days
The month with the most sunshine days is November (17.2 days).
The month with the least sunshine days is July (12.9 days).
Average UV index in September
Charlton, MA
- Average UV index in September: 4
The months with the highest UV index are June and July (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
Charlton, MA
- Average cloud cover in September: 42
The month with the most cloud cover is March (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 37).
Average visibility in September
Charlton, MA
- Average visibility in September: 5mi
The months with the highest visibility are March, April, November and December (6mi).
The months with the lowest visibility are January, February, May, June, July, August, September and October (5mi).





