Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
A moderate decline in average high-temperatures is noted in September, moving from a warm 81°F (27.2°C) in August to a pleasant 72.9°F (22.7°C). The nighttime temperature, during September, averages of 55.6°F (13.1°C).Humidity
The average relative humidity in September is 76%.Rainfall
The month with the least rainfall is September, when the rain falls for 8.6 days and typically collects 0.79" (20mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 29min.On the first day of September, sunrise is at 6:11 am and sunset at 7:19 pm. On the last day of the month, sunrise is at 6:42 am and sunset at 6:28 pm EDT.
Sunshine
In September, the average sunshine is 8.3h.UV index
In Acton, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for the average person.Note: The maximum daily UV index of 4 during September translates into the following directions:
Put precautions into practice - Ensuring skin and eye safety is a necessity. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Acton in September?
What is the average humidity in September?
What is the driest month?
How much does it rain in September?
When it does not snow?
Does it snow in September?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Acton, MA
- Average high temperature in September: 72.9°F
The warmest month (with the highest average high temperature) is July (82.4°F).
The month with the lowest average high temperature is January (32.5°F).
- Average low temperature in September: 55.6°F
The month with the highest average low temperature is July (63.3°F).
The coldest month (with the lowest average low temperature) is January (20.1°F).
Average pressure in September
Acton, 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
Acton, MA
- Average wind speed in September: 6mph
The windiest month (with the highest average wind speed) is January (8.6mph).
The calmest month (with the lowest average wind speed) is August (5.5mph).
Average humidity in September
Acton, MA
- Average humidity in September: 76%
The month with the highest relative humidity is February (79%).
The month with the lowest relative humidity is April (70%).
Average rainfall in September
Acton, MA
- Average rainfall in September: 0.79"
The wettest month (with the highest rainfall) is October (1.65").
The driest month (with the least rainfall) is September (0.79").
Average rainfall days in September
Acton, MA
- Average rainfall days in September: 8.6 days
The month with the highest number of rainy days is July (13.2 days).
The month with the least rainy days is February (5.4 days).
Average snowfall in September
Acton, MA
- Average snowfall in September: 0"
The month with the highest snowfall is February (2.87").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Acton, MA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Acton, MA
- Average daylight in September: 12h and 3min
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 2min
The month with the most sunshine is August (Average sunshine: 10h and 18min).
The month with the least sunshine is February (Average sunshine: 4h and 30min).
Average sunshine days in September
Acton, MA
- Average sunshine days in September: 19.4 days
The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is April (15.8 days).
Average UV index in September
Acton, 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
Acton, MA
- Average cloud cover in September: 38
The month with the most cloud cover is March (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility in September
Acton, 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).
Acton, Massachusetts, USA
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