September weather forecastRoosevelt, WA
September
Weather in September
September, the first month of the autumn in Roosevelt, is also a moderately hot month, with an average temperature fluctuating between 73.9°F (23.3°C) and 54.9°F (12.7°C).Temperature
Roosevelt observes a minor decrease in the average high-temperature with the arrival of September, falling from August's 84.7°F (29.3°C) to a still warm 73.9°F (23.3°C). In the month of September, Roosevelt's average low-temperature falls to a cool 54.9°F (12.7°C).Humidity
In Roosevelt, the average relative humidity in September is 48%.Rainfall
In Roosevelt, in September, it is raining for 5.5 days, with typically 0.31" (8mm) of accumulated precipitation. In Roosevelt, during the entire year, the rain falls for 107.9 days and collects up to 8.46" (215mm) of precipitation.Snowfall
April through October are months without snowfall.Daylight
In September, the average length of the day is 12h and 31min.On the first day of September, sunrise is at 6:23 am and sunset at 7:38 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 6:42 pm PDT.
Sunshine
In September, the average sunshine is 10.9h.UV index
In September, the average daily maximum UV index 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 in September converts into the following recommendations:
Guard yourself - Avoiding sunburn is suggested. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance. Be on the lookout! Nearly twofold UV radiation from the Sun can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Roosevelt, WA
- Average high temperature in September: 73.9°F
The warmest month (with the highest average high temperature) is July (85.5°F).
The month with the lowest average high temperature is December (36.5°F).
- Average low temperature in September: 54.9°F
The month with the highest average low temperature is August (61.3°F).
The coldest month (with the lowest average low temperature) is December (26.6°F).
Average pressure in September
Roosevelt, WA
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is August (29.93"Hg).
Average wind speed in September
Roosevelt, WA
- Average wind speed in September: 7.5mph
The windiest month (with the highest average wind speed) is June (9.2mph).
The calmest month (with the lowest average wind speed) is January (6.3mph).
Average humidity in September
Roosevelt, WA
- Average humidity in September: 48%
The month with the highest relative humidity is January (83%).
The months with the lowest relative humidity are July and August (40%).
Average rainfall in September
Roosevelt, WA
- Average rainfall in September: 0.31"
The wettest month (with the highest rainfall) is January (1.1").
The driest month (with the least rainfall) is July (0.24").
Average rainfall days in September
Roosevelt, WA
- Average rainfall days in September: 5.5 days
The month with the highest number of rainy days is March (12.3 days).
The month with the least rainy days is July (4.4 days).
Average snowfall in September
Roosevelt, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.86").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Roosevelt, WA
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is December (4.8 days).
The months with the least snowfall days are April, May, June, July, August and October (0 days).
Average daylight in September /
Average sunshine in September
Roosevelt, WA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in September: 10h and 54min
The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 5h and 12min).
Average sunshine days in September
Roosevelt, WA
- Average sunshine days in September: 22.1 days
The month with the most sunshine days is July (25 days).
The month with the least sunshine days is February (14 days).
Average UV index in September
Roosevelt, WA
- 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, November and December (UV index 2).
Average cloud cover in September
Roosevelt, WA
- Average cloud cover in September: 16
The month with the most cloud cover is January (Cloud cover 48).
The month with the least cloud cover is July (Cloud cover 9).
Average visibility in September
Roosevelt, WA
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
