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 in Bellevue indicates a gentle shift in the average high-temperature, receding from August's warm 76.6°F (24.8°C) to an agreeable 70°F (21.1°C). An average temperature of 50°F (10°C) marks the nights in Bellevue, Washington, in September.Humidity
The average relative humidity in September is 74%.Rainfall
In Bellevue, in September, it is raining for 7.5 days, with typically 0.63" (16mm) of accumulated precipitation. Throughout the year, there are 119.1 rainfall days, and 11.97" (304mm) of precipitation is accumulated.Snowfall
April through October are months without snowfall in Bellevue.Daylight
In September, the average length of the day in Bellevue, Washington, is 12h and 33min.On the first day of September in Bellevue, sunrise is at 6:28 am and sunset at 7:48 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 6:49 pm PDT.
Sunshine
The average sunshine in September in Bellevue is 9.3h.UV index
In Bellevue, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for the average person.Note: An average UV index of 4 in September transforms into this advice:
Be cautious. Those with fair skin can be subjected to burns in fewer than 30 minutes. To protect against the Sun's most potent rays, avoid direct exposure around midday. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature in Bellevue?
What is the average humidity in September in Bellevue?
How many days does it rain in September in Bellevue?
When it does not snow in Bellevue?
What is the average length of the day in September in Bellevue?
What time are sunrise and sunset in September in Bellevue?
How many hours of sunshine does Bellevue have in September?
What is the UV index intensity in September in Bellevue?
Average temperature in September
Bellevue, WA
- Average high temperature in September: 70°F
The warmest month (with the highest average high temperature) is August (76.6°F).
The month with the lowest average high temperature is December (42.8°F).
- Average low temperature in September: 50°F
The month with the highest average low temperature is August (53.4°F).
The coldest month (with the lowest average low temperature) is February (34.5°F).
Average pressure in September
Bellevue, WA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).
Average wind speed in September
Bellevue, WA
- Average wind speed in September: 3.7mph
The windiest month (with the highest average wind speed) is March (5.1mph).
The calmest month (with the lowest average wind speed) is August (3.4mph).
Average humidity in September
Bellevue, WA
- Average humidity in September: 74%
The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is July (69%).
Average rainfall in September
Bellevue, WA
- Average rainfall in September: 0.63"
The wettest month (with the highest rainfall) is December (2.01").
The driest month (with the least rainfall) is July (0.24").
Average rainfall days in September
Bellevue, WA
- Average rainfall days in September: 7.5 days
The month with the highest number of rainy days is March (13.7 days).
The month with the least rainy days is August (4.1 days).
Average snowfall in September
Bellevue, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.77").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Bellevue, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Bellevue, WA
- Average daylight in September: 12h and 3min
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 2min
The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 4h and 12min).
Average sunshine days in September
Bellevue, WA
- Average sunshine days in September: 20.5 days
The month with the most sunshine days is August (24.9 days).
The month with the least sunshine days is February (13.8 days).
Average UV index in September
Bellevue, 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
Bellevue, WA
- Average cloud cover in September: 34
The month with the most cloud cover is December (Cloud cover 56).
The month with the least cloud cover is August (Cloud cover 25).
Average visibility in September
Bellevue, WA
- Average visibility in September: 6mi
The months with the highest visibility are May, June, July, August and September (6mi).
The months with the lowest visibility are January, February, March, April, October, November and December (5mi).
Bellevue, Washington, USA
Weather forecast for your location
2. Allow the app to use your location