September weather forecastNewton, MA

September
Weather in September
September brings a noticeable change in Newton's weather, with the summer heat beginning to wane. September days can expect temperatures from 56.3°F (13.5°C) to 73°F (22.8°C), ushering the season of harvests. While the wind speeds experience a minor increase, they do not significantly impact the prevailing conditions. Coupled with dropping temperatures, the shortening daylight hints towards the upcoming fall. Hence, September acts as a month of transition, bidding goodbye to the summer and progressively welcoming autumn.Temperature
The arrival of September signals a subtle shift in temperature, down from a moderately hot 81°F (27.2°C) in August to an agreeable 73°F (22.8°C). September's nights observe an average temperature of 56.3°F (13.5°C).Humidity
In September, the average relative humidity is 76%.Rainfall
September is the month with the least rainfall. Rain falls for 6.6 days and accumulates 0.24" (6mm) of precipitation.Snowfall
In Newton, snow does not fall in June through October.Daylight
In Newton, the average length of the day in September is 12h and 28min.On the first day of September in Newton, Massachusetts, sunrise is at 6:10 am and sunset at 7:18 pm. On the last day of the month, sunrise is at 6:41 am and sunset at 6:27 pm EDT.
Sunshine
In September, the average sunshine is 8.6h.UV index
The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for the average person.Note: In September, the maximum UV index of 4 suggests this advice:
Stay alert. Light-skinned people could suffer burns in less than 30 minutes. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Newton, MA
- Average high temperature in September: 73°F
The warmest month (with the highest average high temperature) is July (81.9°F).
The month with the lowest average high temperature is January (33.6°F).
- Average low temperature in September: 56.3°F
The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (21.7°F).
Average pressure in September
Newton, 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
Newton, MA
- Average wind speed in September: 6.3mph
The windiest month (with the highest average wind speed) is January (9.1mph).
The calmest month (with the lowest average wind speed) is August (5.8mph).
Average humidity in September
Newton, MA
- Average humidity in September: 76%
The month with the highest relative humidity is February (78%).
The month with the lowest relative humidity is April (70%).
Average rainfall in September
Newton, MA
- Average rainfall in September: 0.24"
The wettest month (with the highest rainfall) is November (0.67").
The driest month (with the least rainfall) is September (0.24").
Average rainfall days in September
Newton, MA
- Average rainfall days in September: 6.6 days
The month with the highest number of rainy days is July (10.2 days).
The month with the least rainy days is February (4.1 days).
Average snowfall in September
Newton, MA
- Average snowfall in September: 0"
The month with the highest snowfall is December (0.91").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
Newton, MA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (4.9 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Newton, 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 36min
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
Newton, MA
- Average sunshine days in September: 21.4 days
The months with the most sunshine days are January and November (22.5 days).
The month with the least sunshine days is June (17.5 days).
Average UV index in September
Newton, 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
Newton, 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
Newton, MA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).





