September weather forecastFairfield, WA
September
Weather in September
September, the first month of the autumn in Fairfield, is also an agreeable month, with an average temperature fluctuating between 48.2°F (9°C) and 72.5°F (22.5°C).Temperature
September implies a gentle temperature shift, with average high-temperatures reducing from August's moderately hot 83.3°F (28.5°C) to an agreeable 72.5°F (22.5°C). September's nights exhibit a sharp contrast from day highs, with an average temperature of 48.2°F (9°C).Humidity
The average relative humidity in September is 52%.Rainfall
In September, the rain falls for 7.9 days. Throughout September, 0.63" (16mm) of precipitation is accumulated. In Fairfield, during the entire year, the rain falls for 125.4 days and collects up to 17.28" (439mm) of precipitation.Snowfall
January through May, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.2 snowfall days, it receives 0.35" (9mm) of snow. In Fairfield, Washington, during the entire year, snow falls for 56.4 days and aggregates up to 37.4" (950mm) of snow.Daylight
In September, the average length of the day is 12h and 32min.On the first day of the month, sunrise is at 6:08 am and sunset at 7:28 pm. On the last day of September, sunrise is at 6:47 am and sunset at 6:29 pm PDT.
Sunshine
In Fairfield, the average sunshine in September is 10.1h.UV index
In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV radiation for average individuals.Note: A maximum UV index of 4 in September translates into the following recommendations:
Undertake protective steps - Recommendations to avoid sunburn are issued. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration. Note well! The intensity of the Sun's UV rays can be nearly doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Fairfield, WA
- Average high temperature in September: 72.5°F
The warmest month (with the highest average high temperature) is August (83.3°F).
The month with the lowest average high temperature is December (32°F).
- Average low temperature in September: 48.2°F
The month with the highest average low temperature is August (55.9°F).
The coldest month (with the lowest average low temperature) is December (21.9°F).
Average pressure in September
Fairfield, WA
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.19"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).
Average wind speed in September
Fairfield, WA
- Average wind speed in September: 4.9mph
The windiest month (with the highest average wind speed) is April (6.1mph).
The calmest month (with the lowest average wind speed) is December (4.7mph).
Average humidity in September
Fairfield, WA
- Average humidity in September: 52%
The month with the highest relative humidity is January (91%).
The month with the lowest relative humidity is August (43%).
Average rainfall in September
Fairfield, WA
- Average rainfall in September: 0.63"
The wettest month (with the highest rainfall) is January (2.28").
The driest months (with the least rainfall) are July and August (0.35").
Average rainfall days in September
Fairfield, WA
- Average rainfall days in September: 7.9 days
The month with the highest number of rainy days is March (16 days).
The month with the least rainy days is July (5.1 days).
Average snowfall in September
Fairfield, WA
- Average snowfall in September: 0.35"
The month with the highest snowfall is January (10.51").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Fairfield, WA
- Average snowfall days in September: 0.2 days
The month with the highest number of snowfall days is December (13.9 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Fairfield, WA
- Average daylight in September: 12h and 30min
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 6min
The month with the most sunshine is August (Average sunshine: 12h and 0min).
The months with the least sunshine are January and December (Average sunshine: 3h and 48min).
Average sunshine days in September
Fairfield, WA
- Average sunshine days in September: 20.8 days
The month with the most sunshine days is July (24.3 days).
The month with the least sunshine days is March (10.3 days).
Average UV index in September
Fairfield, WA
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Fairfield, WA
- Average cloud cover in September: 21
The month with the most cloud cover is January (Cloud cover 62).
The months with the least cloud cover are July and August (Cloud cover 13).
Average visibility in September
Fairfield, 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 and December (4mi).
