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
September is characterized by a mild reduction in the average high-temperature, from a warm 82.4°F (28°C) in August to a still moderately hot 76.6°F (24.8°C). Washington measures a considerable dip from daytime highs with an average low-temperature of 48°F (8.9°C) during September.Humidity
In Washington, the average relative humidity in September is 44%.Rainfall
In September, the rain falls for 3.8 days. Throughout September, 0.47" (12mm) of precipitation is accumulated. Throughout the year, there are 72.9 rainfall days, and 36.06" (916mm) of precipitation is accumulated.Snowfall
January through June, September through December are months with snowfall. September is the first month it typically snows in Washington. Throughout September, in the average 0.2 snowfall days, it receives 0.35" (9mm) of snow. Throughout the year, in Washington, there are 53.3 snowfall days, and 151.57" (3850mm) of snow is accumulated.Daylight
In September, the average length of the day in Washington is 12h and 26min.On the first day of the month, sunrise is at 6:32 am and sunset at 7:33 pm. On the last day of September, in Washington, sunrise is at 6:59 am and sunset at 6:46 pm PDT.
Sunshine
In September, the average sunshine is 11.2h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for ordinary individuals.Note: In September, the average maximum UV index of 4 translates into the following recommendations:
Act with care - The need to guard against sun damage is communicated. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense. Notice this! Nearly double the intensity of the Sun's UV radiation can be caused by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature in Washington?
What is the average humidity in September in Washington?
How much does it rain in Washington in September?
When does it start snowing in Washington?
How many hours of daylight does Washington have in September?
What time are sunrise and sunset in September in Washington?
How many hours of sunshine does Washington have in September?
What is the UV index intensity in September in Washington?
Average temperature in September
Washington, CA
- Average high temperature in September: 76.6°F
The warmest month (with the highest average high temperature) is July (83.5°F).
The month with the lowest average high temperature is December (43.7°F).
- Average low temperature in September: 48°F
The month with the highest average low temperature is July (52.9°F).
The coldest month (with the lowest average low temperature) is December (29.1°F).
Average pressure in September
Washington, CA
- Average pressure in September: 29.93"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
Washington, CA
- Average wind speed in September: 5.2mph
The windiest month (with the highest average wind speed) is February (6.3mph).
The calmest month (with the lowest average wind speed) is August (5.1mph).
Average humidity in September
Washington, CA
- Average humidity in September: 44%
The month with the highest relative humidity is March (80%).
The month with the lowest relative humidity is July (39%).
Average rainfall in September
Washington, CA
- Average rainfall in September: 0.47"
The wettest month (with the highest rainfall) is March (7.09").
The driest month (with the least rainfall) is July (0.08").
Average rainfall days in September
Washington, CA
- Average rainfall days in September: 3.8 days
The month with the highest number of rainy days is April (11 days).
The month with the least rainy days is July (1.8 days).
Average snowfall in September
Washington, CA
- Average snowfall in September: 0.35"
The month with the highest snowfall is March (37.6").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Washington, CA
- Average snowfall days in September: 0.2 days
The month with the highest number of snowfall days is March (11.7 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Washington, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 11h and 1min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 5h and 36min).
Average sunshine days in September
Washington, CA
- Average sunshine days in September: 25.7 days
The month with the most sunshine days is July (28 days).
The month with the least sunshine days is March (12.6 days).
Average UV index in September
Washington, CA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Washington, CA
- Average cloud cover in September: 9
The month with the most cloud cover is March (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 5).
Average visibility in September
Washington, CA
- Average visibility in September: 6mi
The months with the highest visibility are May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March and April (5mi).
Washington, California, USA
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