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, Onion Creek's weather changes as the average high-temperature falls from a moderately hot 81.1°F (27.3°C) in August to an agreeable 69.8°F (21°C). Onion Creek, after hot September days, encounters a marked drop to an average nighttime temperature of 42.8°F (6°C).Humidity
The average relative humidity in September in Onion Creek is 61%.Rainfall
In Onion Creek, in September, it is raining for 10.2 days, with typically 1.02" (26mm) of accumulated precipitation. In Onion Creek, during the entire year, the rain falls for 156.3 days and collects up to 16.18" (411mm) of precipitation.Snowfall
Months with snowfall are January through April, September through December. September is the first month it typically snows. Throughout September, in the average 0.3 snowfall days, it receives 0.39" (10mm) of snow. Throughout the year, there are 53.2 snowfall days, and 25.16" (639mm) of snow is accumulated.Daylight
The average length of the day in September in Onion Creek, Washington, is 12h and 34min.On the first day of September, sunrise is at 6:09 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 6:31 pm PDT.
Sunshine
In September, the average sunshine is 10.2h.UV index
The average daily maximum UV index in September is 3. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for ordinary individuals.Note: The average daily UV index of 3 in September transforms into the following instructions:
Heed the precautions - Protecting the skin and eyes from damage is compulsory. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Be watchful! The reflection of snow can enhance the intensity of the Sun's UV radiation nearly double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature in Onion Creek?
What is the average humidity in September in Onion Creek?
How much does it rain in Onion Creek in September?
When does it start snowing in Onion Creek?
What is the average length of the day in September in Onion Creek?
What time are sunrise and sunset in September in Onion Creek?
How long on average sun shines in September in Onion Creek?
What is the UV index intensity in September in Onion Creek?
Average temperature in September
Onion Creek, WA
- Average high temperature in September: 69.8°F
The warmest month (with the highest average high temperature) is August (81.1°F).
The month with the lowest average high temperature is December (28.9°F).
- Average low temperature in September: 42.8°F
The month with the highest average low temperature is August (50.5°F).
The coldest month (with the lowest average low temperature) is February (16°F).
Average pressure in September
Onion Creek, WA
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is January (30.19"Hg).
The months with the lowest atmospheric pressure are June and August (29.92"Hg).
Average wind speed in September
Onion Creek, WA
- Average wind speed in September: 3.4mph
The windiest month (with the highest average wind speed) is April (3.9mph).
The calmest months (with the lowest average wind speed) are January, February and December (3mph).
Average humidity in September
Onion Creek, WA
- Average humidity in September: 61%
The month with the highest relative humidity is January (94%).
The month with the lowest relative humidity is August (50%).
Average rainfall in September
Onion Creek, WA
- Average rainfall in September: 1.02"
The wettest month (with the highest rainfall) is May (1.93").
The driest month (with the least rainfall) is August (0.39").
Average rainfall days in September
Onion Creek, WA
- Average rainfall days in September: 10.2 days
The month with the highest number of rainy days is March (18.4 days).
The month with the least rainy days is August (6.1 days).
Average snowfall in September
Onion Creek, WA
- Average snowfall in September: 0.39"
The month with the highest snowfall is January (6.61").
The months with the least snowfall are May, June, July and August (0").
Average snowfall days in September
Onion Creek, WA
- Average snowfall days in September: 0.3 days
The month with the highest number of snowfall days is December (13.7 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Onion Creek, WA
- Average daylight in September: 12h and 4min
The month with the longest days is June (Average daylight: 16h and 6min).
The month with the shortest days is December (Average daylight: 8h and 18min).
- Average sunshine in September: 10h and 1min
The month with the most sunshine is August (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in September
Onion Creek, WA
- Average sunshine days in September: 17.6 days
The month with the most sunshine days is August (20.8 days).
The month with the least sunshine days is March (9 days).
Average UV index in September
Onion Creek, 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, February, November and December (UV index 1).
Average cloud cover in September
Onion Creek, WA
- Average cloud cover in September: 23
The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 14).
Average visibility in September
Onion Creek, WA
- Average visibility in September: 6mi
The months with the highest visibility are May, June, July, August and September (6mi).
The month with the lowest visibility is January (2mi).
Onion Creek, Washington, USA
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