September weather forecastStevenson, WA
September
Weather in September
The first month of the autumn, September, is also an enjoyable month in Stevenson, Washington, with an average temperature ranging between max 67.5°F (19.7°C) and min 46.2°F (7.9°C).Temperature
In the transition to September, Stevenson observes a drop in the average high-temperature, moving from a warm 76.6°F (24.8°C) in August to an enjoyable 67.5°F (19.7°C). Stevenson registers a consistent average low-temperature of 46.2°F (7.9°C) during September.Humidity
In September, the average relative humidity is 71%.Rainfall
In Stevenson, in September, it is raining for 10.6 days, with typically 1.69" (43mm) of accumulated precipitation. Throughout the year, there are 181 rainfall days, and 43.15" (1096mm) of precipitation is accumulated.Snowfall
May through October are months without snowfall.Daylight
In Stevenson, the average length of the day in September is 12h and 31min.On the first day of September, sunrise is at 6:29 am and sunset at 7:44 pm. On the last day of the month, sunrise is at 7:05 am and sunset at 6:48 pm PDT.
Sunshine
In Stevenson, the average sunshine in September is 9h.UV index
The average daily maximum UV index in September is 3. A UV Index estimate of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for average individuals.Note: An average UV index of 3 in September transforms into this advice:
Be mindful. Those with pale skin might receive burns in fewer than 30 minutes. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Stevenson, WA
- Average high temperature in September: 67.5°F
The warmest month (with the highest average high temperature) is August (76.6°F).
The month with the lowest average high temperature is December (37.2°F).
- Average low temperature in September: 46.2°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 (27.7°F).
Average pressure in September
Stevenson, WA
- Average pressure in September: 30"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is August (29.98"Hg).
Average wind speed in September
Stevenson, WA
- Average wind speed in September: 4.5mph
The windiest month (with the highest average wind speed) is January (6.5mph).
The calmest month (with the lowest average wind speed) is August (4.4mph).
Average humidity in September
Stevenson, WA
- Average humidity in September: 71%
The month with the highest relative humidity is February (89%).
The months with the lowest relative humidity are July and August (66%).
Average rainfall in September
Stevenson, WA
- Average rainfall in September: 1.69"
The wettest month (with the highest rainfall) is January (7.48").
The driest month (with the least rainfall) is July (0.31").
Average rainfall days in September
Stevenson, WA
- Average rainfall days in September: 10.6 days
The month with the highest number of rainy days is March (21.7 days).
The month with the least rainy days is August (5 days).
Average snowfall in September
Stevenson, WA
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.33").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Stevenson, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (4.4 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Stevenson, 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 48min).
- Average sunshine in September: 9h and 0min
The months with the most sunshine are July and August (Average sunshine: 11h and 6min).
The month with the least sunshine is February (Average sunshine: 3h and 24min).
Average sunshine days in September
Stevenson, WA
- Average sunshine days in September: 18.1 days
The month with the most sunshine days is August (24 days).
The month with the least sunshine days is February (7.1 days).
Average UV index in September
Stevenson, WA
- Average UV index in September: 3
The months with the highest UV index are June and July (UV index 5).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Stevenson, WA
- Average cloud cover in September: 36
The month with the most cloud cover is February (Cloud cover 67).
The month with the least cloud cover is August (Cloud cover 23).
Average visibility in September
Stevenson, WA
- Average visibility in September: 5mi
The months with the highest visibility are July and August (6mi).
The months with the lowest visibility are January, February, March, November and December (4mi).
