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 an agreeable 72.7°F (22.6°C). In September, the temperature drops to an average of 54.5°F (12.5°C) at night.Humidity
The average relative humidity in September is 78%.Rainfall
September is the month with the least rainfall. Rain falls for 12.2 days and accumulates 1.54" (39mm) of precipitation.Snowfall
June through October are months without snowfall.Daylight
In September, the average length of the day is 12h and 28min.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
The average sunshine in September is 8.2h.UV index
The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for ordinary individuals.Note: The maximum daily UV index of 4 during September translates into the following directions:
Take precautions - Protection against sunburn is recommended. Limiting sun exposure during midday hours helps in reducing the harmful effects of UV radiation. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the average humidity in September?
What is the driest month?
How many days does it rain in September?
When it does not snow?
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?
How high is the UV index in September?
Average temperature in September
Grafton, MA
- Average high temperature in September: 72.7°F
The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (32.5°F).
- Average low temperature in September: 54.5°F
The month with the highest average low temperature is July (62.6°F).
The coldest month (with the lowest average low temperature) is January (20.5°F).
Average pressure in September
Grafton, MA
- Average pressure in September: 30.06"Hg
The month with the highest atmospheric pressure is November (30.07"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Grafton, MA
- Average wind speed in September: 6.2mph
The windiest months (with the highest average wind speed) are January, February and March (8.9mph).
The calmest month (with the lowest average wind speed) is August (5.7mph).
Average humidity in September
Grafton, MA
- Average humidity in September: 78%
The month with the highest relative humidity is February (80%).
The month with the lowest relative humidity is April (71%).
Average rainfall in September
Grafton, MA
- Average rainfall in September: 1.54"
The wettest month (with the highest rainfall) is December (3.15").
The driest month (with the least rainfall) is September (1.54").
Average rainfall days in September
Grafton, MA
- Average rainfall days in September: 12.2 days
The month with the highest number of rainy days is July (16.8 days).
The month with the least rainy days is January (7.7 days).
Average snowfall in September
Grafton, MA
- Average snowfall in September: 0"
The month with the highest snowfall is March (4.92").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
Grafton, MA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (8.4 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Grafton, 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 12min).
- Average sunshine in September: 8h and 1min
The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in September
Grafton, MA
- Average sunshine days in September: 15.5 days
The month with the most sunshine days is November (18 days).
The month with the least sunshine days is July (11.8 days).
Average UV index in September
Grafton, 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
Grafton, MA
- Average cloud cover in September: 40
The month with the most cloud cover is March (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 36).
Average visibility in September
Grafton, MA
- Average visibility in September: 5mi
The months with the highest visibility are January, March, April, October, November and December (6mi).
The months with the lowest visibility are February, May, June, July, August and September (5mi).
Grafton, Massachusetts, USA
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