September weather forecastMaple Valley, WA
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Maple Valley, Washington, with an average temperature varying between 47.3°F (8.5°C) and 68.4°F (20.2°C).Temperature
With the commencement of September, Maple Valley records a moderate temperature decline, with the average high easing from August's warm 75.4°F (24.1°C) to a pleasant 68.4°F (20.2°C). Throughout the month of September, Maple Valley expects an average low of 47.3°F (8.5°C).Humidity
The average relative humidity in September in Maple Valley is 75%.Rainfall
In Maple Valley, in September, it is raining for 11.9 days, with typically 1.73" (44mm) of accumulated precipitation. Throughout the year, there are 182.4 rainfall days, and 36.77" (934mm) of precipitation is accumulated.Snowfall
May through October are months without snowfall.Daylight
In Maple Valley, the average length of the day in September is 12h and 32min.On the first day of September, sunrise is at 6:28 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:06 am and sunset at 6:48 pm PDT.
Sunshine
In September, the average sunshine is 9.1h.UV index
In September, the average daily maximum UV index is 3. A UV Index estimate of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for average individuals.Note: A maximum UV index of 3 in September translates into the following recommendations:
Be careful. Light complexion individuals might get burns in fewer than 30 minutes. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays. Take to heart! Snow reflection can almost magnify the Sun's UV radiation twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Maple Valley, WA
- Average high temperature in September: 68.4°F
The warmest month (with the highest average high temperature) is August (75.4°F).
The month with the lowest average high temperature is December (40.8°F).
- Average low temperature in September: 47.3°F
The month with the highest average low temperature is August (50.2°F).
The coldest month (with the lowest average low temperature) is February (31.6°F).
Average pressure in September
Maple Valley, WA
- Average pressure in September: 30"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The months with the lowest atmospheric pressure are August and September (30"Hg).
Average wind speed in September
Maple Valley, WA
- Average wind speed in September: 3.7mph
The windiest month (with the highest average wind speed) is January (5.2mph).
The calmest month (with the lowest average wind speed) is August (3.5mph).
Average humidity in September
Maple Valley, WA
- Average humidity in September: 75%
The months with the highest relative humidity are January and February (86%).
The month with the lowest relative humidity is July (70%).
Average rainfall in September
Maple Valley, WA
- Average rainfall in September: 1.73"
The wettest month (with the highest rainfall) is December (5.43").
The driest month (with the least rainfall) is July (0.59").
Average rainfall days in September
Maple Valley, WA
- Average rainfall days in September: 11.9 days
The month with the highest number of rainy days is March (20.5 days).
The month with the least rainy days is August (6.7 days).
Average snowfall in September
Maple Valley, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (4.17").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Maple Valley, WA
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is February (6 days).
The months with the least snowfall days are June, July, August and October (0 days).
Average daylight in September /
Average sunshine in September
Maple Valley, 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: 9h and 6min
The month with the most sunshine is August (Average sunshine: 10h and 42min).
The months with the least sunshine are January and December (Average sunshine: 4h and 6min).
Average sunshine days in September
Maple Valley, WA
- Average sunshine days in September: 16.8 days
The month with the most sunshine days is August (22 days).
The month with the least sunshine days is February (8.4 days).
Average UV index in September
Maple Valley, WA
- Average UV index in September: 3
The month with the highest UV index is July (UV index 5).
The month with the lowest UV index is November (UV index 1).
Average cloud cover in September
Maple Valley, WA
- Average cloud cover in September: 37
The months with the most cloud cover are January, February, March and December (Cloud cover 57).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in September
Maple Valley, WA
- Average visibility in September: 5mi
The months with the highest visibility are July and August (6mi).
The months with the lowest visibility are January, February and December (4mi).
