September weather forecastHooper, WA
September
Weather in September
September, the first month of the autumn in Hooper, is still a warm month, with an average temperature varying between 56.3°F (13.5°C) and 74.3°F (23.5°C).Temperature
The beginning of September involves a decrease in the average high-temperature, transitioning from a warm 85.1°F (29.5°C) in August to a still moderately hot 74.3°F (23.5°C). September's average low-temperature reading settles at a moderate 56.3°F (13.5°C).Humidity
In September, the average relative humidity is 42%.Rainfall
In Hooper, in September, during 6.6 rainfall days, 0.39" (10mm) of precipitation is typically accumulated. Throughout the year, there are 109 rainfall days, and 10.59" (269mm) of precipitation is accumulated.Snowfall
January through April, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow. Throughout the year, there are 28.2 snowfall days, and 12.48" (317mm) of snow is accumulated.Daylight
In Hooper, Washington, the average length of the day in September is 12h and 32min.On the first day of September, sunrise is at 6:13 am and sunset at 7:31 pm. On the last day of the month, sunrise is at 6:51 am and sunset at 6:33 pm PDT.
Sunshine
The average sunshine in September is 10.5h.UV index
The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for ordinary individuals.Note: A daily high UV index of 4 in September leads to these guidelines:
Proceed with care. Light skin individuals may be exposed to burns in fewer than 30 minutes. Minimize direct exposure to the Sun during midday when its radiation is at its peak. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized. Heed this! Snow reflection can almost augment the UV radiation of the sun by double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Hooper, WA
- Average high temperature in September: 74.3°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is December (33.8°F).
- Average low temperature in September: 56.3°F
The month with the highest average low temperature is August (64.6°F).
The coldest month (with the lowest average low temperature) is December (25.2°F).
Average pressure in September
Hooper, WA
- Average pressure in September: 29.95"Hg
The month with the highest atmospheric pressure is January (30.19"Hg).
The month with the lowest atmospheric pressure is August (29.9"Hg).
Average wind speed in September
Hooper, WA
- Average wind speed in September: 8mph
The windiest month (with the highest average wind speed) is March (9.8mph).
The calmest month (with the lowest average wind speed) is August (7.3mph).
Average humidity in September
Hooper, WA
- Average humidity in September: 42%
The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is August (34%).
Average rainfall in September
Hooper, WA
- Average rainfall in September: 0.39"
The wettest month (with the highest rainfall) is March (1.38").
The driest months (with the least rainfall) are July and August (0.31").
Average rainfall days in September
Hooper, WA
- Average rainfall days in September: 6.6 days
The month with the highest number of rainy days is March (13.6 days).
The month with the least rainy days is July (4.2 days).
Average snowfall in September
Hooper, WA
- Average snowfall in September: 0.04"
The month with the highest snowfall is February (3.54").
The months with the least snowfall are May, June, July and August (0").
Average snowfall days in September
Hooper, WA
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is December (7.8 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Hooper, WA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 48min).
The month with the shortest days is December (Average daylight: 8h and 36min).
- Average sunshine in September: 10h and 30min
The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 4h and 36min).
Average sunshine days in September
Hooper, WA
- Average sunshine days in September: 21.9 days
The month with the most sunshine days is July (25.3 days).
The month with the least sunshine days is March (14.2 days).
Average UV index in September
Hooper, WA
- Average UV index in September: 4
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Hooper, WA
- Average cloud cover in September: 18
The month with the most cloud cover is January (Cloud cover 52).
The month with the least cloud cover is July (Cloud cover 11).
Average visibility in September
Hooper, 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).





