September weather forecast
Jamestown, RI

Weather in September

The first month of the autumn, September, is still a pleasant month in Jamestown, Rhode Island, with an average temperature varying between 71.4°F (21.9°C) and 59.7°F (15.4°C).

Temperature

In Jamestown, the average high-temperature in September slightly decreases from a moderately hot 77.7°F (25.4°C) in August to an agreeable 71.4°F (21.9°C). In September, the average low-temperature is 59.7°F (15.4°C).

Humidity

In Jamestown, the average relative humidity in September is 78%.

Rainfall

The month with the least rainfall is September, when the rain falls for 11.6 days and typically collects 1.42" (36mm) of precipitation.

Snowfall

April, June through October are months without snowfall in Jamestown.

Ocean temperature

In Jamestown, the average water temperature is 67.3°F (19.6°C).
Note: Swimming in 67.3°F (19.6°C) is not enjoyable for the majority. Controlling breathing becomes progressively more difficult as surface water temperature decreases below 69.8°F (21°C).

Daylight

In September, the average length of the day is 12h and 28min.
On the first day of the month, sunrise is at 6:11 am and sunset at 7:18 pm. On the last day of September, sunrise is at 6:41 am and sunset at 6:29 pm EDT.

Sunshine

In Jamestown, the average sunshine in September is 8.7h.

UV index

In Jamestown, Rhode Island, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.
Note: The average daily UV index of 4 in September transform into the following instructions:
Take precautions - Protection against sunburn is recommended. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
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FAQ

What is the average humidity in September in Jamestown?

In September, the average relative humidity in Jamestown, Rhode Island, is 78%.

What is the driest month in Jamestown?

September is the month with the least rainfall in Jamestown. Rain falls for 11.6 days and accumulates 1.42" (36mm) of precipitation.

How many days does it rain in September in Jamestown?

In Jamestown, during September, the rain falls for 11.6 days and regularly aggregates up to 1.42" (36mm) of precipitation.

When it does not snow in Jamestown?

April, June through October are months without snowfall.

How cold is the water in September in Jamestown?

In September, the average ocean temperature in Jamestown, Rhode Island, is 67.3°F (19.6°C). For swimming, a surface water temperature of 67.3°F (19.6°C) is not enjoyable for the majority. It is not considered safe, as controlling breathing becomes progressively more difficult as water temperature decreases below 69.8°F (21°C).

How many hours of daylight does Jamestown have in September?

In Jamestown, Rhode Island, the average day length in September is 12h and 28min.

When is the sunrise / sunset in September in Jamestown?

In September, on the first day of the month, sunrise is at 6:11 am and sunset at 7:18 pm. On the last day of the month, sunrise is at 6:41 am and sunset at 6:29 pm EDT.

How long on average sun shines in September in Jamestown?

In September, the average sunshine duration is 8.7h.

What is the UV index intensity in September in Jamestown?

In Jamestown, Rhode Island, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate health threat from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Jamestown, RI

Average temperature in September - Jamestown, RI
  • Average high temperature in September: 71.4°F

The warmest month (with the highest average high temperature) is July (78.3°F).
The month with the lowest average high temperature is January (36.1°F).

  • Average low temperature in September: 59.7°F

The month with the highest average low temperature is July (66.7°F).
The coldest month (with the lowest average low temperature) is January (26.4°F).

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Average pressure in September
Jamestown, RI

Average pressure in September - Jamestown, RI
  • 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 (29.93"Hg).

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Average wind speed in September
Jamestown, RI

Average wind speed in September - Jamestown, RI
  • Average wind speed in September: 9mph

The windiest month (with the highest average wind speed) is January (12.1mph).
The calmest month (with the lowest average wind speed) is August (8.1mph).

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Average humidity in September
Jamestown, RI

Average humidity in September - Jamestown, RI
  • Average humidity in September: 78%

The month with the highest relative humidity is June (81%).
The month with the lowest relative humidity is March (73%).

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Average rainfall in September
Jamestown, RI

Average rainfall in September - Jamestown, RI
  • Average rainfall in September: 1.42"

The wettest month (with the highest rainfall) is October (3.27").
The driest month (with the least rainfall) is September (1.42").

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Average rainfall days in September
Jamestown, RI

Average rainfall days in September - Jamestown, RI
  • Average rainfall days in September: 11.6 days

The month with the highest number of rainy days is April (15.6 days).
The month with the least rainy days is January (8.3 days).

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Average snowfall in September
Jamestown, RI

Average snowfall in September - Jamestown, RI
  • Average snowfall in September: 0"

The month with the highest snowfall is February (2.76").
The months with the least snowfall are April, June, July, August, September and October (0").

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Average snowfall days in September
Jamestown, RI

Average snowfall days in September - Jamestown, RI
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (6.6 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

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Average sea temperature in September
Jamestown, RI

Average sea temperature in September - Jamestown, RI
  • Average sea temperature in September: 67.2°F

The best month for swimming (with the highest average sea temperature) is August (69.6°F).
The coldest month (with the lowest average sea temperature) is February (38.1°F).

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Average daylight in September /
Average sunshine in September
Jamestown, RI

Average daylight in September / Average sunshine in September - Jamestown, RI
  • Average daylight in September: 12h and 28min

The month with the longest days is June (Average daylight: 15h and 8min).
The month with the shortest days is December (Average daylight: 9h and 14min).

  • Average sunshine in September: 8h and 42min

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 48min).

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Average sunshine days in September
Jamestown, RI

Average sunshine days in September - Jamestown, RI
  • Average sunshine days in September: 15.8 days

The month with the most sunshine days is November (17.7 days).
The month with the least sunshine days is April (12.3 days).

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Average UV index in September
Jamestown, RI

Average UV index in September - Jamestown, RI
  • 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 and December (UV index 2).

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Average cloud cover in September
Jamestown, RI

Average cloud cover in September - Jamestown, RI
  • Average cloud cover in September: 33

The month with the most cloud cover is March (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 29).

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Average visibility in September
Jamestown, RI

Average visibility in September - Jamestown, RI
  • 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).

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