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
In September, the average high-temperature decreases from 85.6°F (29.8°C) in August to a still moderately hot 75.4°F (24.1°C). September in Clarkston, Washington, is characterized by a distinct thermal shift, with nighttime lows averaging at a cool 52.7°F (11.5°C).Humidity
The average relative humidity in September in Clarkston is 45%.Rainfall
In Clarkston, during September, the rain falls for 5.1 days and regularly aggregates up to 0.31" (8mm) of precipitation. Throughout the year, in Clarkston, Washington, there are 116.2 rainfall days, and 8.23" (209mm) of precipitation is accumulated.Snowfall
In Clarkston, snow does not fall in April through September.Daylight
The average length of the day in September is 12h and 32min.On the first day of the month, sunrise is at 6:09 am and sunset at 7:26 pm. On the last day of September, sunrise is at 6:46 am and sunset at 6:29 pm PDT.
Sunshine
In Clarkston, the average sunshine in September is 10.5h.UV index
In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for average individuals.Note: The maximum UV index of 4 during September translates into these guidelines:
Be mindful. Individuals with a lighter skin tone may suffer burns in less than 30 minutes. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. Always opt for UVA and UVB-resistant sunglasses on radiant days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September in Clarkston?
What is the average humidity in September in Clarkston?
How many days does it rain in September in Clarkston?
When it does not snow in Clarkston?
Does it snow in Clarkston in September?
How many hours of daylight does Clarkston have in September?
When are sunrise and sunset in September in Clarkston?
How many hours of sunshine does Clarkston have in September?
How high is the UV index in September in Clarkston?
Average temperature in September
Clarkston, WA
- Average high temperature in September: 75.4°F
The warmest month (with the highest average high temperature) is August (85.6°F).
The month with the lowest average high temperature is December (36.5°F).
- Average low temperature in September: 52.7°F
The month with the highest average low temperature is August (59.4°F).
The coldest month (with the lowest average low temperature) is December (24.8°F).
Average pressure in September
Clarkston, WA
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.2"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).
Average wind speed in September
Clarkston, WA
- Average wind speed in September: 4.5mph
The windiest month (with the highest average wind speed) is April (6mph).
The calmest month (with the lowest average wind speed) is August (4.4mph).
Average humidity in September
Clarkston, WA
- Average humidity in September: 45%
The month with the highest relative humidity is January (84%).
The month with the lowest relative humidity is August (38%).
Average rainfall in September
Clarkston, WA
- Average rainfall in September: 0.31"
The wettest month (with the highest rainfall) is March (0.98").
The driest month (with the least rainfall) is August (0.24").
Average rainfall days in September
Clarkston, WA
- Average rainfall days in September: 5.1 days
The months with the highest number of rainy days are March and April (13.8 days).
The month with the least rainy days is August (4.5 days).
Average snowfall in September
Clarkston, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.89").
The months with the least snowfall are April, May, June, July, August and September (0").
Average snowfall days in September
Clarkston, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (4.7 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Clarkston, 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 42min).
- Average sunshine in September: 10h and 3min
The month with the most sunshine is August (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 5h and 0min).
Average sunshine days in September
Clarkston, WA
- Average sunshine days in September: 23.1 days
The month with the most sunshine days is July (23.8 days).
The month with the least sunshine days is February (12.8 days).
Average UV index in September
Clarkston, 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
Clarkston, WA
- Average cloud cover in September: 18
The month with the most cloud cover is February (Cloud cover 48).
The months with the least cloud cover are July and August (Cloud cover 12).
Average visibility in September
Clarkston, WA
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February and December (5mi).
Clarkston, Washington, USA
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