September weather forecastWalnut Grove, WA
September
Weather in September
September, the first month of the autumn in Walnut Grove, is also an agreeable month, with an average temperature fluctuating between 73°F (22.8°C) and 50.7°F (10.4°C).Temperature
With the arrival of September, Walnut Grove notices a mild change in the average high-temperature, sliding from August's warm 80.6°F (27°C) to a pleasant 73°F (22.8°C). Walnut Grove, after an intense day, registers a significant cooling to an average low-temperature of 50.7°F (10.4°C) throughout September.Humidity
The average relative humidity in September is 70%.Rainfall
In Walnut Grove, in September, it is raining for 10.8 days, with typically 1.73" (44mm) of accumulated precipitation. Throughout the year, there are 177.1 rainfall days, and 34.29" (871mm) of precipitation is accumulated.Snowfall
April through October are months without snowfall.Daylight
In September, the average length of the day is 12h and 31min.On the first day of the month, sunrise is at 6:32 am and sunset at 7:47 pm. On the last day of September, sunrise is at 7:08 am and sunset at 6:51 pm PDT.
Sunshine
The average sunshine in September is 9.3h.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: In September, the maximum UV index of 4 translates into these guidelines:
Exercise caution. The susceptibility of light skin individuals to burns is less than 30 minutes. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Walnut Grove, WA
- Average high temperature in September: 73°F
The warmest month (with the highest average high temperature) is August (80.6°F).
The month with the lowest average high temperature is December (43.7°F).
- Average low temperature in September: 50.7°F
The month with the highest average low temperature is August (54°F).
The coldest month (with the lowest average low temperature) is December (34°F).
Average pressure in September
Walnut Grove, WA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).
Average wind speed in September
Walnut Grove, WA
- Average wind speed in September: 3.9mph
The windiest month (with the highest average wind speed) is January (5.5mph).
The calmest month (with the lowest average wind speed) is August (3.8mph).
Average humidity in September
Walnut Grove, WA
- Average humidity in September: 70%
The months with the highest relative humidity are January and February (84%).
The month with the lowest relative humidity is August (65%).
Average rainfall in September
Walnut Grove, WA
- Average rainfall in September: 1.73"
The wettest month (with the highest rainfall) is December (5.08").
The driest month (with the least rainfall) is July (0.35").
Average rainfall days in September
Walnut Grove, WA
- Average rainfall days in September: 10.8 days
The month with the highest number of rainy days is March (20.6 days).
The month with the least rainy days is August (4.9 days).
Average snowfall in September
Walnut Grove, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.42").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Walnut Grove, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.1 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Walnut Grove, WA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).
- Average sunshine in September: 9h and 18min
The month with the most sunshine is August (Average sunshine: 11h and 0min).
The months with the least sunshine are January and February (Average sunshine: 4h and 6min).
Average sunshine days in September
Walnut Grove, WA
- Average sunshine days in September: 17.7 days
The month with the most sunshine days is July (24.1 days).
The month with the least sunshine days is February (7.9 days).
Average UV index in September
Walnut Grove, WA
- Average UV index in September: 4
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 2).
Average cloud cover in September
Walnut Grove, WA
- Average cloud cover in September: 33
The month with the most cloud cover is February (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 23).
Average visibility in September
Walnut Grove, WA
- Average visibility in September: 6mi
The months with the highest visibility are July, August and September (6mi).
The months with the lowest visibility are January, February, March, April, May, June, October, November and December (5mi).
