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
The commencement of September involves a temperature shift, with the average high-temperature dropping from a warm 83.1°F (28.4°C) in August to a pleasant 71.6°F (22°C). A significant temperature decrease to an average a frosty 44.6°F (7°C) characterizes Valley's nighttime temperatures during September.Humidity
In Valley, the average relative humidity in September is 57%.Rainfall
In Valley, in September, it is raining for 7.8 days, with typically 0.83" (21mm) of accumulated precipitation. Throughout the year, there are 141.6 rainfall days, and 17.56" (446mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through April, September through December. September is the first month it typically snows. Throughout September, in the average 0.2 snowfall days, it receives 0.63" (16mm) of snow. Throughout the year, there are 57.8 snowfall days, and 34.09" (866mm) of snow is accumulated.Daylight
In Valley, the average length of the day in September is 12h and 34min.On the first day of the month, sunrise is at 6:09 am and sunset at 7:31 pm. On the last day of September, sunrise is at 6:49 am and sunset at 6:31 pm PDT.
Sunshine
In September, the average sunshine in Valley, Washington, is 10.3h.UV index
In September, the average daily maximum UV index in Valley is 3. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for ordinary individuals.Note: In September, the maximum UV index of 3 transforms into these recommendations:
Guard yourself - An obligation to protect skin and eyes from harm exists. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. Employ a hat with a wide brim for robust protection, cutting UV exposure by half. Stay alert! Snow's reflective properties can almost double the UV radiation from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature in Valley?
What is the average humidity in September in Valley?
How many days does it rain in September in Valley?
When does it start to snow in Valley?
How many hours of daylight does Valley have in September?
When are sunrise and sunset in September in Valley?
How long on average sun shines in September in Valley?
What is the UV index intensity in September in Valley?
Average temperature in September
Valley, WA
- Average high temperature in September: 71.6°F
The warmest month (with the highest average high temperature) is August (83.1°F).
The month with the lowest average high temperature is December (29.8°F).
- Average low temperature in September: 44.6°F
The month with the highest average low temperature is August (51.8°F).
The coldest month (with the lowest average low temperature) is December (18.7°F).
Average pressure in September
Valley, WA
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.19"Hg).
The months with the lowest atmospheric pressure are June and August (29.91"Hg).
Average wind speed in September
Valley, WA
- Average wind speed in September: 4mph
The windiest month (with the highest average wind speed) is April (4.7mph).
The calmest months (with the lowest average wind speed) are January and December (3.5mph).
Average humidity in September
Valley, WA
- Average humidity in September: 57%
The month with the highest relative humidity is January (94%).
The month with the lowest relative humidity is August (47%).
Average rainfall in September
Valley, WA
- Average rainfall in September: 0.83"
The wettest month (with the highest rainfall) is January (2.2").
The driest month (with the least rainfall) is August (0.35").
Average rainfall days in September
Valley, WA
- Average rainfall days in September: 7.8 days
The month with the highest number of rainy days is March (17.1 days).
The month with the least rainy days is August (5.6 days).
Average snowfall in September
Valley, WA
- Average snowfall in September: 0.63"
The month with the highest snowfall is January (10.47").
The months with the least snowfall are May, June, July and August (0").
Average snowfall days in September
Valley, WA
- Average snowfall days in September: 0.2 days
The month with the highest number of snowfall days is December (15.4 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Valley, WA
- Average daylight in September: 12h and 4min
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 24min).
- Average sunshine in September: 10h and 2min
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 36min).
Average sunshine days in September
Valley, WA
- Average sunshine days in September: 19.5 days
The month with the most sunshine days is August (22.9 days).
The month with the least sunshine days is March (9.3 days).
Average UV index in September
Valley, 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
Valley, WA
- Average cloud cover in September: 21
The month with the most cloud cover is January (Cloud cover 63).
The month with the least cloud cover is August (Cloud cover 13).
Average visibility in September
Valley, 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 and February (3mi).
Valley, Washington, USA
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