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 onset of September is marked by a minor decrease in temperature, transitioning from a moderately hot 79.3°F (26.3°C) in August to an agreeable 72°F (22.2°C). Williamsburg records an average low-temperature of 52.7°F (11.5°C) throughout the month of September.Humidity
In September, the average relative humidity is 78%.Rainfall
In Williamsburg, during September, the rain falls for 10.3 days and regularly aggregates up to 0.98" (25mm) of precipitation. Throughout the year, there are 134.1 rainfall days, and 14.84" (377mm) of precipitation is accumulated.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 September, sunrise is at 6:16 am and sunset at 7:24 pm. On the last day of the month, sunrise is at 6:47 am and sunset at 6:33 pm EDT.
Sunshine
In Williamsburg, the average sunshine in September is 8.7h.UV index
In Williamsburg, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV radiation for ordinary individuals.Note: The average daily UV index of 4 in September transforms into the following instructions:
Be vigilant - Preventing sunburn is recommended. The solar radiation around mid-day is intense; avoid the Sun and stay safe. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage.
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Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
How many hours of daylight does Williamsburg have in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
Williamsburg, MA
- Average high temperature in September: 72°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 (30.4°F).
- Average low temperature in September: 52.7°F
The month with the highest average low temperature is July (60.8°F).
The coldest month (with the lowest average low temperature) is January (18°F).
Average pressure in September
Williamsburg, MA
- Average pressure in September: 30.06"Hg
The month with the highest atmospheric pressure is November (30.08"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Williamsburg, MA
- Average wind speed in September: 5.5mph
The windiest months (with the highest average wind speed) are January, February and March (8mph).
The calmest month (with the lowest average wind speed) is August (5mph).
Average humidity in September
Williamsburg, MA
- Average humidity in September: 78%
The month with the highest relative humidity is February (82%).
The month with the lowest relative humidity is April (72%).
Average rainfall in September
Williamsburg, MA
- Average rainfall in September: 0.98"
The wettest month (with the highest rainfall) is October (1.61").
The driest month (with the least rainfall) is February (0.91").
Average rainfall days in September
Williamsburg, MA
- Average rainfall days in September: 10.3 days
The month with the highest number of rainy days is May (13.9 days).
The month with the least rainy days is January (8.5 days).
Average snowfall in September
Williamsburg, MA
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.85").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
Williamsburg, MA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (7.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Williamsburg, 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 months with the most sunshine are July and August (Average sunshine: 10h and 18min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in September
Williamsburg, MA
- Average sunshine days in September: 17.1 days
The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is June (13.7 days).
Average UV index in September
Williamsburg, MA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).
Average cloud cover in September
Williamsburg, MA
- Average cloud cover in September: 37
The months with the most cloud cover are February and March (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility in September
Williamsburg, MA
- Average visibility in September: 5mi
The months with the highest visibility are January, March, April, November and December (6mi).
The months with the lowest visibility are February, May, June, July, August, September and October (5mi).
Williamsburg, Massachusetts, USA
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