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
Welcoming September, White Swan observes a shift in the average high-temperature, falling from August's moderately hot 83.1°F (28.4°C) to an agreeable 72°F (22.2°C). September nights showcase a dramatic shift from daytime highs to an average temperature of 50°F (10°C).Humidity
The average relative humidity in September is 53%.Rainfall
In White Swan, in September, it is raining for 6.5 days, with typically 0.47" (12mm) of accumulated precipitation. Throughout the year, in White Swan, there are 112.8 rainfall days, and 10.28" (261mm) of precipitation is accumulated.Snowfall
January through April, September, November and December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.16" (4mm) of snow. Throughout the year, in White Swan, there are 19.9 snowfall days, and 12.36" (314mm) of snow is accumulated.Daylight
In September, the average length of the day in White Swan is 12h and 32min.On the first day of the month, sunrise is at 6:24 am and sunset at 7:41 pm. On the last day of September, in White Swan, sunrise is at 7:01 am and sunset at 6:43 pm PDT.
Sunshine
The average sunshine in September is 10.9h.UV index
The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for the average person.Note: The average daily UV index of 4 in September transforms into the following instructions:
Undertake precautions - Guarding against sun damage is counselled. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key. Note well! The intensity of the Sun's UV rays can be nearly doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September in White Swan?
What is the average humidity in September?
How many days does it rain in September?
When does it start snowing?
What is the average length of the day in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
White Swan, WA
- Average high temperature in September: 72°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 (35.2°F).
- Average low temperature in September: 50°F
The month with the highest average low temperature is August (56.8°F).
The coldest month (with the lowest average low temperature) is December (23.9°F).
Average pressure in September
White Swan, WA
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is August (29.94"Hg).
Average wind speed in September
White Swan, WA
- Average wind speed in September: 5.9mph
The windiest month (with the highest average wind speed) is April (6.9mph).
The calmest month (with the lowest average wind speed) is December (4.5mph).
Average humidity in September
White Swan, WA
- Average humidity in September: 53%
The month with the highest relative humidity is January (84%).
The month with the lowest relative humidity is August (43%).
Average rainfall in September
White Swan, WA
- Average rainfall in September: 0.47"
The wettest month (with the highest rainfall) is January (1.61").
The driest month (with the least rainfall) is July (0.12").
Average rainfall days in September
White Swan, WA
- Average rainfall days in September: 6.5 days
The month with the highest number of rainy days is March (13.7 days).
The month with the least rainy days is July (3.1 days).
Average snowfall in September
White Swan, WA
- Average snowfall in September: 0.16"
The month with the highest snowfall is February (3.5").
The months with the least snowfall are May, June, July, August and October (0").
Average snowfall days in September
White Swan, WA
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is December (5.5 days).
The months with the least snowfall days are May, June, July, August and October (0 days).
Average daylight in September /
Average sunshine in September
White Swan, WA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in September: 10h and 5min
The months with the most sunshine are July and August (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 5h and 24min).
Average sunshine days in September
White Swan, WA
- Average sunshine days in September: 21.1 days
The month with the most sunshine days is July (25.9 days).
The month with the least sunshine days is February (12.6 days).
Average UV index in September
White Swan, 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
White Swan, WA
- Average cloud cover in September: 16
The month with the most cloud cover is January (Cloud cover 44).
The months with the least cloud cover are July and August (Cloud cover 9).
Average visibility in September
White Swan, WA
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and December (5mi).
White Swan, Washington, USA
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