September weather forecastForks, WA

September
Weather in September
September offers a gentle transition towards autumn while maintaining an average high temperature of 64.2°F (17.9°C). Accompanied by calm winds and a steady daylight duration, the month promises comfortable warmth. The slight uptick in rainfall fosters a greener environment, acting as a prelude to the impending fall foliage. A scattering of clouds softens the sunlight, casting a dreamy sheen over Forks. Thus, September, with its harmonious weather conditions, sets the stage for the upcoming seasonal transition.Temperature
The arrival of September coincides with an average high-temperature of an enjoyable 64.2°F (17.9°C), indicating a minimal shift from August's 68.2°F (20.1°C). Throughout September, the average low-temperature records at a frosty 49.3°F (9.6°C).Humidity
The average relative humidity in September is 81%.Rainfall
In Forks, in September, it is raining for 7.4 days, with typically 0.43" (11mm) of accumulated precipitation. Throughout the year, there are 109.2 rainfall days, and 10.79" (274mm) of precipitation is accumulated.Snowfall
In Forks, snow does not fall in April through December.Daylight
In Forks, the average length of the day in September is 12h and 33min.On the first day of September, sunrise is at 6:36 am and sunset at 7:57 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 6:57 pm PDT.
Sunshine
In September, the average sunshine is 8.5h.UV index
In Forks, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for ordinary individuals.Note: The daily high UV index of 4 in September translates into this advice:
Ensure safety - Sun damage prevention is strongly urged. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. Experience reduced UV exposure by about half when donning a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Forks, WA
- Average high temperature in September: 64.2°F
The warmest month (with the highest average high temperature) is August (68.2°F).
The month with the lowest average high temperature is December (44.2°F).
- Average low temperature in September: 49.3°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 (37°F).
Average pressure in September
Forks, WA
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is July (30.08"Hg).
The month with the lowest atmospheric pressure is March (29.99"Hg).
Average wind speed in September
Forks, WA
- Average wind speed in September: 5.1mph
The windiest month (with the highest average wind speed) is January (8mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).
Average humidity in September
Forks, WA
- Average humidity in September: 81%
The months with the highest relative humidity are January and December (86%).
The months with the lowest relative humidity are May and July (80%).
Average rainfall in September
Forks, WA
- Average rainfall in September: 0.43"
The wettest month (with the highest rainfall) is January (2.36").
The driest month (with the least rainfall) is July (0.16").
Average rainfall days in September
Forks, WA
- Average rainfall days in September: 7.4 days
The month with the highest number of rainy days is March (13.3 days).
The month with the least rainy days is August (3 days).
Average snowfall in September
Forks, WA
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.75").
The months with the least snowfall are April, May, June, July, August, September, October, November and December (0").
Average snowfall days in September
Forks, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.2 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
Forks, WA
- Average daylight in September: 12h and 36min
The month with the longest days is June (Average daylight: 16h and 0min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in September: 8h and 30min
The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in September
Forks, WA
- Average sunshine days in September: 19 days
The month with the most sunshine days is August (24.9 days).
The month with the least sunshine days is February (12.2 days).
Average UV index in September
Forks, WA
- Average UV index in September: 4
The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Forks, WA
- Average cloud cover in September: 39
The month with the most cloud cover is January (Cloud cover 62).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility in September
Forks, WA
- Average visibility in September: 5mi
The months with the highest visibility are January, February, March, April, October, November and December (6mi).
The months with the lowest visibility are May, June, July, August and September (5mi).





