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
The beginning of September subtly marks a decrease in the average high-temperature, transitioning from a warm 81°F (27.2°C) in August to a pleasant 73°F (22.8°C). During the month of September, an average low-temperature of 56.3°F (13.5°C) is recorded.Humidity
The average relative humidity in September in Chestnut Hill is 76%.Rainfall
September is the month with the least rainfall in Chestnut Hill. Rain falls for 6.6 days and accumulates 0.24" (6mm) of precipitation.Snowfall
In Chestnut Hill, snow does not fall in June through October.Daylight
The average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:10 am and sunset at 7:18 pm. On the last day of September, 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 estimate of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for average individuals.Note: In September, the UV index of 4 transforms into the following advice:
Proceed with care. Light skin individuals may be exposed to burns in fewer than 30 minutes. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in September?
What is the average humidity in September in Chestnut Hill?
What is the driest month?
How much does it rain in September?
When it does not snow?
What is the average length of the day in September?
When are sunrise and sunset in September in Chestnut Hill?
How long on average sun shines in September?
What is the UV index intensity in September?
Average temperature in September
Chestnut Hill, 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
Chestnut Hill, 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
Chestnut Hill, 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
Chestnut Hill, 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
Chestnut Hill, 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
Chestnut Hill, 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
Chestnut Hill, 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
Chestnut Hill, 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
Chestnut Hill, 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 4min
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
Chestnut Hill, 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
Chestnut Hill, 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
Chestnut Hill, 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
Chestnut Hill, 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).
Chestnut Hill, Massachusetts, USA
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