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 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
With September's arrival, Stevenson sees a decrease in average high-temperatures, moving from a warm 76.6°F (24.8°C) in August to a comfortable 67.5°F (19.7°C). Throughout the month of September, the average temperature dips to a frosty 46.2°F (7.9°C) at night.Humidity
In September, the average relative humidity is 71%.Rainfall
In Stevenson, during September, the rain falls for 10.6 days and regularly aggregates up to 1.69" (43mm) of precipitation. In Stevenson, during the entire year, the rain falls for 181 days and collects up to 43.15" (1096mm) of precipitation.Snowfall
In Stevenson, snow does not fall in May through October.Daylight
The average length of the day in September is 12h and 31min.On the first day of the month, sunrise is at 6:29 am and sunset at 7:44 pm. On the last day of September, 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
In September, the average daily maximum UV index is 3. A UV Index reading of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for ordinary individuals.Note: A maximum UV index of 3 in September translates into the following recommendations:
Take care. Persons with lighter skin might suffer burns in less than 30 minutes. Avoiding the Sun during its peak radiation time around midday is a healthy practice. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
How many hours of daylight does Stevenson have in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
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 3min
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).
Stevenson, Washington, USA
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