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
During the shift to September, a minor reduction in average high-temperature is observed, shifting from a warm 80.1°F (26.7°C) in August to a pleasant 72.5°F (22.5°C). Nighttime temperatures hover around an average low of 54°F (12.2°C) in September.Humidity
In September, the average relative humidity is 78%.Rainfall
September is the month with the least rainfall. Rain falls for 12.3 days and accumulates 1.57" (40mm) of precipitation.Snowfall
In Sterling, Massachusetts, snow does not fall in June through September.Daylight
In September, the average length of the day is 12h and 29min.On the first day of the month, sunrise is at 6:12 am and sunset at 7:20 pm. On the last day of September, sunrise is at 6:43 am and sunset at 6:29 pm EDT.
Sunshine
In Sterling, the average sunshine in September is 8.3h.UV index
In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for average individuals.Note: A maximum daily UV index of 4 during September morphs into the following directions:
Put precautions into practice - Guidance to elude sunburn is provided. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in Sterling in September?
What is the average humidity in September in Sterling?
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 many hours of sunshine does Sterling have in September?
What is the UV index intensity in September?
Average temperature in September
Sterling, MA
- Average high temperature in September: 72.5°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 (31.5°F).
- Average low temperature in September: 54°F
The month with the highest average low temperature is July (62.2°F).
The coldest month (with the lowest average low temperature) is January (19.8°F).
Average pressure in September
Sterling, 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
Sterling, MA
- Average wind speed in September: 5.9mph
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
Sterling, MA
- Average humidity in September: 78%
The month with the highest relative humidity is February (81%).
The month with the lowest relative humidity is April (71%).
Average rainfall in September
Sterling, MA
- Average rainfall in September: 1.57"
The wettest month (with the highest rainfall) is December (2.91").
The driest month (with the least rainfall) is September (1.57").
Average rainfall days in September
Sterling, MA
- Average rainfall days in September: 12.3 days
The month with the highest number of rainy days is July (16 days).
The month with the least rainy days is February (7.3 days).
Average snowfall in September
Sterling, MA
- Average snowfall in September: 0"
The month with the highest snowfall is February (6.1").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Sterling, MA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (9.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Sterling, 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 12min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in September
Sterling, MA
- Average sunshine days in September: 15.1 days
The month with the most sunshine days is November (17.4 days).
The month with the least sunshine days is July (12.8 days).
Average UV index in September
Sterling, 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
Sterling, MA
- Average cloud cover in September: 39
The month with the most cloud cover is March (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility in September
Sterling, MA
- Average visibility in September: 5mi
The months with the highest visibility are March, April, October, November and December (6mi).
The months with the lowest visibility are January, February, May, June, July, August and September (5mi).
Sterling, Massachusetts, USA
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