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
Plain experiences a temperature shift at the start of September, with average high-temperatures adjusting from a moderately hot 77.5°F (25.3°C) in August to a comfortable 66.4°F (19.1°C). A steep decline to a frosty 43.2°F (6.2°C) characterizes the September nights.Humidity
In Plain, the average relative humidity in September is 65%.Rainfall
In September, in Plain, the rain falls for 10.3 days. Throughout September, 1.06" (27mm) of precipitation is accumulated. Throughout the year, there are 159.9 rainfall days, and 25.63" (651mm) of precipitation is accumulated.Snowfall
January through May, September through December are months with snowfall. September is the first month it typically snows in Plain. Throughout September, in the average 0.2 snowfall days, it receives 0.39" (10mm) of snow. Throughout the year, in Plain, Washington, there are 73.4 snowfall days, and 57.99" (1473mm) of snow is accumulated.Daylight
In September, the average length of the day is 12h and 33min.On the first day of the month, sunrise is at 6:22 am and sunset at 7:42 pm. On the last day of September, sunrise is at 7:01 am and sunset at 6:43 pm PDT.
Sunshine
In Plain, the average sunshine in September is 10.5h.UV index
In Plain, Washington, the average daily maximum UV index in September is 3. A UV Index estimate of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for ordinary individuals.Note: The maximum daily UV index of 3 during September translates into the following directions:
Be mindful. Individuals with a lighter skin tone may suffer burns in less than 30 minutes. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days. On your guard! Snow's reflection can almost double the intensity of the Sun's UV radiation.
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Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Plain in September?
What is the average humidity in September in Plain?
How many days does it rain in September in Plain?
When does it start to snow in Plain?
How many hours of daylight does Plain have in September?
When is the sunrise / sunset in September in Plain?
How many hours of sunshine does Plain have in September?
What is the UV index intensity in September in Plain?
Average temperature in September
Plain, WA
- Average high temperature in September: 66.4°F
The warmest month (with the highest average high temperature) is August (77.5°F).
The month with the lowest average high temperature is December (30.6°F).
- Average low temperature in September: 43.2°F
The month with the highest average low temperature is August (49.6°F).
The coldest month (with the lowest average low temperature) is December (18.7°F).
Average pressure in September
Plain, WA
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is August (29.95"Hg).
Average wind speed in September
Plain, WA
- Average wind speed in September: 4.7mph
The windiest month (with the highest average wind speed) is June (5.7mph).
The calmest month (with the lowest average wind speed) is December (3.5mph).
Average humidity in September
Plain, WA
- Average humidity in September: 65%
The month with the highest relative humidity is January (92%).
The months with the lowest relative humidity are July and August (56%).
Average rainfall in September
Plain, WA
- Average rainfall in September: 1.06"
The wettest month (with the highest rainfall) is January (4.33").
The driest month (with the least rainfall) is July (0.43").
Average rainfall days in September
Plain, WA
- Average rainfall days in September: 10.3 days
The month with the highest number of rainy days is March (18.2 days).
The month with the least rainy days is August (6.3 days).
Average snowfall in September
Plain, WA
- Average snowfall in September: 0.39"
The month with the highest snowfall is January (16.73").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Plain, WA
- Average snowfall days in September: 0.2 days
The month with the highest number of snowfall days is December (17 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Plain, WA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in September: 10h and 3min
The month with the most sunshine is August (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in September
Plain, WA
- Average sunshine days in September: 16.5 days
The month with the most sunshine days is August (21.9 days).
The month with the least sunshine days is February (6.8 days).
Average UV index in September
Plain, WA
- Average UV index in September: 3
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January and February (UV index 1).
Average cloud cover in September
Plain, WA
- Average cloud cover in September: 25
The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is August (Cloud cover 15).
Average visibility in September
Plain, WA
- Average visibility in September: 6mi
The months with the highest visibility are April, May, June, July, August, September and October (6mi).
The months with the lowest visibility are January, February, March, November and December (4mi).
Plain, Washington, USA
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