September weather forecastJefferson, MA
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Jefferson, Massachusetts, with an average temperature ranging between max 71.4°F (21.9°C) and min 53.6°F (12°C).Temperature
September's onset brings a negligible change in high-temperatures, falling from a moderately hot 79°F (26.1°C) in August to an agreeable 71.4°F (21.9°C). An average nighttime temperature of 53.6°F (12°C) is noted in Jefferson during the month of September.Humidity
In Jefferson, the average relative humidity in September is 79%.Rainfall
September is the month with the least rainfall. Rain falls for 13.1 days and accumulates 1.69" (43mm) of precipitation.Snowfall
In Jefferson, snow does not fall in June through September.Daylight
In September, the average length of the day is 12h and 28min.On the first day of the month, sunrise is at 6:13 am and sunset at 7:21 pm. On the last day of September, sunrise is at 6:44 am and sunset at 6:30 pm EDT.
Sunshine
In September, the average sunshine is 8.1h.UV index
In Jefferson, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for the average person.Note: The maximum daily UV index of 4 in September interprets into the following recommendations:
Guard yourself - An obligation to protect skin and eyes from harm exists. When the Sun is at its strongest around midday, find shade and limit exposure. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Jefferson, MA
- Average high temperature in September: 71.4°F
The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (30.9°F).
- Average low temperature in September: 53.6°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 (18.9°F).
Average pressure in September
Jefferson, MA
- Average pressure in September: 30.06"Hg
The month with the highest atmospheric pressure is November (30.07"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Jefferson, MA
- Average wind speed in September: 6mph
The windiest month (with the highest average wind speed) is January (9.1mph).
The calmest month (with the lowest average wind speed) is August (5.6mph).
Average humidity in September
Jefferson, 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
Jefferson, MA
- Average rainfall in September: 1.69"
The wettest month (with the highest rainfall) is December (2.76").
The driest month (with the least rainfall) is September (1.69").
Average rainfall days in September
Jefferson, MA
- Average rainfall days in September: 13.1 days
The month with the highest number of rainy days is May (16.3 days).
The months with the least rainy days are January and February (6.8 days).
Average snowfall in September
Jefferson, MA
- Average snowfall in September: 0"
The month with the highest snowfall is February (6.06").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Jefferson, MA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (9.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Jefferson, 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 6min
The months with the most sunshine are July and August (Average sunshine: 10h and 0min).
The month with the least sunshine is February (Average sunshine: 4h and 30min).
Average sunshine days in September
Jefferson, MA
- Average sunshine days in September: 15.1 days
The month with the most sunshine days is November (17.8 days).
The month with the least sunshine days is June (12.8 days).
Average UV index in September
Jefferson, 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
Jefferson, MA
- Average cloud cover in September: 41
The month with the most cloud cover is March (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 36).
Average visibility in September
Jefferson, MA
- Average visibility in September: 5mi
The months with the highest visibility are April, November and December (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September and October (5mi).
