September weather forecastCoulee Dam, WA
September
Weather in September
September, the first month of the autumn in Coulee Dam, is also an agreeable month, with an average temperature varying between 53.2°F (11.8°C) and 72.7°F (22.6°C).Temperature
In September, the meteorological conditions alter, with the average high-temperature shifting from a warm 84.2°F (29°C) in August to an agreeable 72.7°F (22.6°C). During September, the average low-temperature is recorded at a cool 53.2°F (11.8°C).Humidity
In September, the average relative humidity in Coulee Dam is 45%.Rainfall
In Coulee Dam, during September, the rain falls for 5.5 days and regularly aggregates up to 0.43" (11mm) of precipitation. Throughout the year, there are 102.1 rainfall days, and 9.65" (245mm) 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 0.1 snowfall days, it receives 0.08" (2mm) of snow. In Coulee Dam, during the entire year, snow falls for 33.4 days and aggregates up to 14.65" (372mm) of snow.Daylight
In September, the average length of the day is 12h and 33min.On the first day of September in Coulee Dam, sunrise is at 6:15 am and sunset at 7:36 pm. On the last day of the month, sunrise is at 6:54 am and sunset at 6:36 pm PDT.
Sunshine
In September, the average sunshine in Coulee Dam is 10.7h.UV index
In Coulee Dam, 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 unprotected exposure to Sun's UV rays for ordinary individuals.Note: In September, a daily UV index of 4 turns into the following recommendations:
Undertake precautions - Obligation exists to protect against skin and eye damage. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration. Remember to consider! The UV radiation from the Sun can be intensified nearly twice by the reflection of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Coulee Dam, WA
- Average high temperature in September: 72.7°F
The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is December (31.6°F).
- Average low temperature in September: 53.2°F
The month with the highest average low temperature is August (61.3°F).
The coldest month (with the lowest average low temperature) is December (21.4°F).
Average pressure in September
Coulee Dam, WA
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.18"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).
Average wind speed in September
Coulee Dam, WA
- Average wind speed in September: 5.8mph
The windiest month (with the highest average wind speed) is April (7mph).
The calmest month (with the lowest average wind speed) is January (4.9mph).
Average humidity in September
Coulee Dam, WA
- Average humidity in September: 45%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is August (36%).
Average rainfall in September
Coulee Dam, WA
- Average rainfall in September: 0.43"
The wettest months (with the highest rainfall) are May and December (1.18").
The driest months (with the least rainfall) are July and August (0.2").
Average rainfall days in September
Coulee Dam, WA
- Average rainfall days in September: 5.5 days
The month with the highest number of rainy days is March (12.1 days).
The month with the least rainy days is August (3.2 days).
Average snowfall in September
Coulee Dam, WA
- Average snowfall in September: 0.08"
The month with the highest snowfall is January (4.41").
The months with the least snowfall are May, June, July and August (0").
Average snowfall days in September
Coulee Dam, WA
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is December (10.5 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Coulee Dam, WA
- Average daylight in September: 12h and 36min
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 30min).
- Average sunshine in September: 10h and 42min
The month with the most sunshine is August (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in September
Coulee Dam, WA
- Average sunshine days in September: 23.3 days
The month with the most sunshine days is August (25.8 days).
The month with the least sunshine days is March (14.7 days).
Average UV index in September
Coulee Dam, WA
- Average UV index in September: 4
The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is November (UV index 1).
Average cloud cover in September
Coulee Dam, WA
- Average cloud cover in September: 18
The month with the most cloud cover is January (Cloud cover 55).
The months with the least cloud cover are July and August (Cloud cover 12).
Average visibility in September
Coulee Dam, WA
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and December (4mi).
