September weather forecastMill River, MA
September
Weather in September
The first month of the autumn, September, is also an agreeable month in Mill River, Massachusetts, with an average temperature ranging between max 70.9°F (21.6°C) and min 51.3°F (10.7°C).Temperature
With September's onset, the weather reveals a slight temperature decrease, transitioning from a warm 78.4°F (25.8°C) in August to a pleasant 70.9°F (21.6°C). In Mill River, the nighttime temperature averages to a fresh 51.3°F (10.7°C) during September.Humidity
In Mill River, the average relative humidity in September is 80%.Rainfall
In Mill River, in September, during 12.7 rainfall days, 2.24" (57mm) of precipitation is typically accumulated. Throughout the year, there are 157.8 rainfall days, and 31.69" (805mm) of precipitation is accumulated.Snowfall
In Mill River, snow does not fall in June through September.Daylight
In Mill River, Massachusetts, the average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:19 am and sunset at 7:26 pm. On the last day of September, sunrise is at 6:49 am and sunset at 6:35 pm EDT.
Sunshine
In Mill River, the average sunshine in September is 8.5h.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 exposure to the Sun's UV radiation for ordinary individuals.Note: In September, the maximum UV index of 4 suggests this advice:
Be mindful. Those with pale skin might receive burns in fewer than 30 minutes. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Mill River, MA
- Average high temperature in September: 70.9°F
The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is January (29.1°F).
- Average low temperature in September: 51.3°F
The month with the highest average low temperature is July (59.4°F).
The coldest month (with the lowest average low temperature) is January (17.1°F).
Average pressure in September
Mill River, MA
- Average pressure in September: 30.06"Hg
The month with the highest atmospheric pressure is November (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Mill River, MA
- Average wind speed in September: 5.6mph
The windiest months (with the highest average wind speed) are January and March (8.4mph).
The calmest months (with the lowest average wind speed) are July and August (5.2mph).
Average humidity in September
Mill River, MA
- Average humidity in September: 80%
The month with the highest relative humidity is February (84%).
The month with the lowest relative humidity is April (75%).
Average rainfall in September
Mill River, MA
- Average rainfall in September: 2.24"
The wettest month (with the highest rainfall) is October (3.03").
The driest month (with the least rainfall) is January (2.13").
Average rainfall days in September
Mill River, MA
- Average rainfall days in September: 12.7 days
The month with the highest number of rainy days is May (16.6 days).
The month with the least rainy days is January (8.2 days).
Average snowfall in September
Mill River, MA
- Average snowfall in September: 0"
The month with the highest snowfall is February (6.89").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Mill River, MA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (13.2 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Mill River, 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 30min
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: 3h and 54min).
Average sunshine days in September
Mill River, MA
- Average sunshine days in September: 15.5 days
The months with the most sunshine days are September and November (15.5 days).
The month with the least sunshine days is February (11.1 days).
Average UV index in September
Mill River, MA
- Average UV index in September: 4
The months with the highest UV index are May, June, July and August (UV index 5).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Mill River, MA
- Average cloud cover in September: 40
The month with the most cloud cover is February (Cloud cover 57).
The months with the least cloud cover are July and August (Cloud cover 37).
Average visibility in September
Mill River, MA
- Average visibility in September: 5mi
The month with the highest visibility is April (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September, October, November and December (5mi).





