September weather forecastKapowsin, WA
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Kapowsin, Washington, with an average temperature varying between 46°F (7.8°C) and 68.2°F (20.1°C).Temperature
The transition to September results in a modest reduction in average high-temperature, moving from a warm 75°F (23.9°C) in August to a pleasant 68.2°F (20.1°C). Kapowsin measures a considerable dip from daytime highs with an average low-temperature of 46°F (7.8°C) during September.Humidity
In September, the average relative humidity is 75%.Rainfall
In Kapowsin, in September, during 12.3 rainfall days, 1.93" (49mm) of precipitation is typically accumulated. Throughout the year, in Kapowsin, there are 182.2 rainfall days, and 37.83" (961mm) of precipitation is accumulated.Snowfall
In Kapowsin, snow does not fall in May through October.Daylight
In Kapowsin, Washington, the average length of the day in September is 12h and 32min.On the first day of the month, sunrise is at 6:29 am and sunset at 7:47 pm. On the last day of September, sunrise is at 7:07 am and sunset at 6:49 pm PDT.
Sunshine
In Kapowsin, the average sunshine in September is 9.1h.UV index
In Kapowsin, Washington, 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 exposure to the Sun's UV rays for ordinary individuals.Note: In September, the maximum UV index of 3 transforms into these recommendations:
Make use of precautions - Suggestions to resist sunburn are communicated. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Kapowsin, WA
- Average high temperature in September: 68.2°F
The warmest month (with the highest average high temperature) is August (75°F).
The month with the lowest average high temperature is December (41.2°F).
- Average low temperature in September: 46°F
The month with the highest average low temperature is August (49.5°F).
The coldest month (with the lowest average low temperature) is December (31.1°F).
Average pressure in September
Kapowsin, WA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).
Average wind speed in September
Kapowsin, WA
- Average wind speed in September: 3.8mph
The windiest month (with the highest average wind speed) is January (5mph).
The calmest month (with the lowest average wind speed) is August (3.6mph).
Average humidity in September
Kapowsin, WA
- Average humidity in September: 75%
The month with the highest relative humidity is February (88%).
The month with the lowest relative humidity is July (70%).
Average rainfall in September
Kapowsin, WA
- Average rainfall in September: 1.93"
The wettest month (with the highest rainfall) is December (5.71").
The driest month (with the least rainfall) is July (0.43").
Average rainfall days in September
Kapowsin, WA
- Average rainfall days in September: 12.3 days
The month with the highest number of rainy days is March (20.2 days).
The month with the least rainy days is August (6.1 days).
Average snowfall in September
Kapowsin, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (4.84").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Kapowsin, WA
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is February (6 days).
The months with the least snowfall days are June, July, August and October (0 days).
Average daylight in September /
Average sunshine in September
Kapowsin, 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: 9h and 6min
The month with the most sunshine is August (Average sunshine: 10h and 54min).
The month with the least sunshine is December (Average sunshine: 4h and 6min).
Average sunshine days in September
Kapowsin, WA
- Average sunshine days in September: 16.1 days
The month with the most sunshine days is August (22.9 days).
The month with the least sunshine days is February (8 days).
Average UV index in September
Kapowsin, WA
- Average UV index in September: 3
The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Kapowsin, WA
- Average cloud cover in September: 37
The months with the most cloud cover are January, February, March and December (Cloud cover 57).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in September
Kapowsin, WA
- Average visibility in September: 5mi
The months with the highest visibility are April, May, June, July, August, September and October (5mi).
The months with the lowest visibility are January, February, March, November and December (4mi).





