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 arrival of September corresponds with a light shift in temperature, down from a warm 76.5°F (24.7°C) in August to a pleasant 69.6°F (20.9°C). Summit's temperature lowers to a mean of 48.6°F (9.2°C) during the nights in September.Humidity
In September, the average relative humidity in Summit is 75%.Rainfall
In Summit, in September, during 12.1 rainfall days, 1.61" (41mm) of precipitation is typically accumulated. Throughout the year, there are 183.4 rainfall days, and 32.48" (825mm) of precipitation is accumulated.Snowfall
In Summit, snow does not fall in April through October.Daylight
The average length of the day in September is 12h and 32min.On the first day of September in Summit, sunrise is at 6:29 am and sunset at 7:48 pm. On the last day of the month, sunrise is at 7:08 am and sunset at 6:50 pm PDT.
Sunshine
In September, the average sunshine in Summit is 9.3h.UV index
In September, the average daily maximum UV index in Summit is 3. A UV Index estimate of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for the average person.Note: In September, the maximum UV index of 3 translates into these guidelines:
Heed the precautions - It is counselled to guard against solar damage. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature in Summit?
What is the average humidity in September in Summit?
How much does it rain in Summit in September?
When it does not snow in Summit?
How many hours of daylight does Summit have in September?
What time are sunrise and sunset in September in Summit?
How many hours of sunshine does Summit have in September?
How high is the UV index in September in Summit?
Average temperature in September
Summit, WA
- Average high temperature in September: 69.6°F
The warmest month (with the highest average high temperature) is August (76.5°F).
The month with the lowest average high temperature is December (42.8°F).
- Average low temperature in September: 48.6°F
The month with the highest average low temperature is August (51.6°F).
The coldest month (with the lowest average low temperature) is December (32.7°F).
Average pressure in September
Summit, 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
Summit, WA
- Average wind speed in September: 3.7mph
The windiest month (with the highest average wind speed) is March (4.9mph).
The calmest month (with the lowest average wind speed) is August (3.5mph).
Average humidity in September
Summit, WA
- Average humidity in September: 75%
The month with the highest relative humidity is January (87%).
The month with the lowest relative humidity is July (69%).
Average rainfall in September
Summit, WA
- Average rainfall in September: 1.61"
The wettest month (with the highest rainfall) is December (4.92").
The driest month (with the least rainfall) is July (0.43").
Average rainfall days in September
Summit, WA
- Average rainfall days in September: 12.1 days
The month with the highest number of rainy days is March (21 days).
The month with the least rainy days is August (6.2 days).
Average snowfall in September
Summit, 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
Summit, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.7 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
Summit, 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 36min).
- Average sunshine in September: 9h and 2min
The month with the most sunshine is August (Average sunshine: 10h and 54min).
The month with the least sunshine is December (Average sunshine: 4h and 12min).
Average sunshine days in September
Summit, WA
- Average sunshine days in September: 16.7 days
The month with the most sunshine days is August (22.3 days).
The month with the least sunshine days is February (8.2 days).
Average UV index in September
Summit, WA
- Average UV index in September: 3
The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January, February, October, November and December (UV index 2).
Average cloud cover in September
Summit, WA
- Average cloud cover in September: 35
The months with the most cloud cover are January and December (Cloud cover 56).
The month with the least cloud cover is August (Cloud cover 25).
Average visibility in September
Summit, 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, March, April, May, June, September, October, November and December (5mi).
Summit, Washington, USA
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