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 sea temperature 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 start of September in Jamestown signals a gentle decrease in the average high-temperature, transitioning from a moderately hot 77.7°F (25.4°C) in August to an agreeable 71.4°F (21.9°C). September in Jamestown is noted for a mean low-temperature of 59.7°F (15.4°C).Humidity
The average relative humidity in September in Jamestown is 78%.Rainfall
The month with the least rainfall in Jamestown, Rhode Island, 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, in September, the average water temperature is 67.3°F (19.6°C).Note: For most people, swimming in water at 67.3°F (19.6°C) is not a pleasurable experience. Breathing control gets harder as the water temperature descends from 69.8°F (21°C) to 59°F (15°C).
Daylight
In Jamestown, Rhode Island, the average length of the day in September is 12h and 28min.On the first day of September in Jamestown, Rhode Island, sunrise is at 6:12 am and sunset at 7:18 pm. On the last day of the month, sunrise is at 6:41 am and sunset at 6:28 pm EDT.
Sunshine
In September, the average sunshine is 8.7h.UV index
In September, the average daily maximum UV index in Jamestown is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for the ordinary person.Note: In September, a regular UV index of 4 translates into these guidelines:
Preventative actions are necessary - The mandate to avoid skin and eye damage is in place. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage.
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Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Jamestown in September?
What is the average humidity in September in Jamestown?
What is the driest month in Jamestown?
How many days does it rain in September in Jamestown?
When it does not snow in Jamestown?
What is the ocean temperature in September in Jamestown?
What is the average length of the day in September in Jamestown?
When is the sunrise / sunset in September in Jamestown?
How long on average sun shines in September in Jamestown?
How high is the UV index in September in Jamestown?
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).
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).
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).
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%).
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").
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).
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").
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).
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).
Average daylight in September /
Average sunshine in September
Jamestown, RI
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- 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 48min).
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).
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).
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).
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).
Jamestown, Rhode Island, USA
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