September weather forecast
Williamstown, VT

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Weather in September

The first month of the autumn, September, is still a refreshing month in Williamstown, Vermont, with an average temperature fluctuating between 48°F (8.9°C) and 67.6°F (19.8°C).

Temperature

The arrival of September signals a subtle shift in temperature, down from a moderately hot 74.8°F (23.8°C) in August to a refreshing 67.6°F (19.8°C). An average temperature of 48°F (8.9°C) is recorded during the nights in September.

Humidity

In September, the average relative humidity is 81%.

Rainfall

September is the month with the least rainfall. Rain falls for 13.1 days and accumulates 2.09" (53mm) of precipitation.

Snowfall

June through September are months without snowfall.

Daylight

The average length of the day in September is 12h and 30min.
On the first day of September, sunrise is at 6:14 am and sunset at 7:25 pm. On the last day of the month, sunrise is at 6:47 am and sunset at 6:32 pm EDT.

Sunshine

The average sunshine in September is 8h.

UV index

The average daily maximum UV index in September is 3. A UV Index reading of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.
Note: In September, a daily maximum UV index of 3 leads to the following instructions:
Preventative actions are necessary - Suggestions to safeguard against sun damage are in order. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. Employ a hat with a wide brim for robust protection, cutting UV exposure by half.

Frequently asked questions

What are September temperatures in Williamstown?

September temperatures vary between a high-temperature of 67.6°F (19.8°C) and a low-temperature of 48°F (8.9°C).

What is the average humidity in September?

In Williamstown, the average relative humidity in September is 81%.

What is the driest month?

The month with the least rainfall is September, when the rain falls for 13.1 days and typically collects 2.09" (53mm) of precipitation.

How many days does it rain in September?

In Williamstown, in September, during 13.1 rainfall days, 2.09" (53mm) of precipitation is typically accumulated.

When it does not snow?

In Williamstown, snow does not fall in June through September.

Does it snow in September?

In Williamstown, in September, it doesn't snow. In October, it regularly snows.

What is the average length of the day in September?

The average day length in September in Williamstown is 12h and 30min.

What time are sunrise and sunset in September?

On the first day of September in Williamstown, sunrise is at 6:14 am and sunset at 7:25 pm. On the last day of the month, sunrise is at 6:47 am and sunset at 6:32 pm EDT.

How many hours of sunshine does Williamstown have in September?

In Williamstown, the average sunshine duration in September is 8h.

What is the UV index reading in September?

The average daily maximum UV index in September is 3. A UV Index value of 3 to 5 symbolizes a moderate health threat from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Williamstown, VT

Average temperature in September - Williamstown, VT
  • Average high temperature in September: 67.6°F

The warmest month (with the highest average high temperature) is July (76.8°F).
The month with the lowest average high temperature is January (23.2°F).

  • Average low temperature in September: 48°F

The month with the highest average low temperature is July (55.2°F).
The coldest month (with the lowest average low temperature) is January (10.8°F).

Average pressure in September
Williamstown, VT

Average pressure in September - Williamstown, VT
  • 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 (29.91"Hg).

Average wind speed in September
Williamstown, VT

Average wind speed in September - Williamstown, VT
  • Average wind speed in September: 5.3mph

The windiest month (with the highest average wind speed) is April (7.3mph).
The calmest month (with the lowest average wind speed) is August (5mph).

Average humidity in September
Williamstown, VT

Average humidity in September - Williamstown, VT
  • Average humidity in September: 81%

The months with the highest relative humidity are January and February (89%).
The month with the lowest relative humidity is May (76%).

Average rainfall in September
Williamstown, VT

Average rainfall in September - Williamstown, VT
  • Average rainfall in September: 2.09"

The wettest month (with the highest rainfall) is June (3.43").
The driest month (with the least rainfall) is September (2.09").

Average rainfall days in September
Williamstown, VT

Average rainfall days in September - Williamstown, VT
  • Average rainfall days in September: 13.1 days

The month with the highest number of rainy days is June (18.8 days).
The month with the least rainy days is January (6.8 days).

Average snowfall in September
Williamstown, VT

Average snowfall in September - Williamstown, VT
  • Average snowfall in September: 0"

The month with the highest snowfall is February (13.31").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Williamstown, VT

Average snowfall days in September - Williamstown, VT
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (22.3 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Williamstown, VT

Average daylight in September / Average sunshine in September - Williamstown, VT
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 8h and 54min).

  • Average sunshine in September: 8h and 0min

The month with the most sunshine is July (Average sunshine: 9h and 48min).
The months with the least sunshine are January and February (Average sunshine: 2h and 42min).

Average sunshine days in September
Williamstown, VT

Average sunshine days in September - Williamstown, VT
  • Average sunshine days in September: 14.6 days

The month with the most sunshine days is September (14.6 days).
The month with the least sunshine days is February (5.5 days).

Average UV index in September
Williamstown, VT

Average UV index in September - Williamstown, VT
  • Average UV index in September: 3

The months with the highest UV index are June and July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 1).

Average cloud cover in September
Williamstown, VT

Average cloud cover in September - Williamstown, VT
  • Average cloud cover in September: 43

The months with the most cloud cover are January and February (Cloud cover 74).
The month with the least cloud cover is July (Cloud cover 39).

Average visibility in September
Williamstown, VT

Average visibility in September - Williamstown, VT
  • Average visibility in September: 5mi

The months with the highest visibility are April, May, June, July, August, September, October and November (5mi).
The months with the lowest visibility are January, February, March and December (4mi).

Williamstown, Vermont, USA

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