September weather forecastCle Elum, WA

September
Weather in September
Cle Elum welcomes fall in September, as the city transitions from summer to the arrival of cooler days. September is an ideal time to visit Cle Elum, as it typically sees decreased temperatures and less rainfall. However, the occasional rainfall seen from 1.1" (28mm) to 2.87" (73mm) is a gentle reminder of the changing seasons. The outdoor activities continue, enhanced with the unique beauty of fall foliage. The transition of the weather pattern signifies the beauty of autumn slowly taking over Cle Elum.Temperature
The commencement of September involves a temperature shift, with the average high-temperature dropping from a moderately hot 75.4°F (24.1°C) in August to a refreshing 64.6°F (18.1°C). September nights in Cle Elum indicate a noticeable temperature drop from the daytime highs, with an average reading lowering to a cold 42.3°F (5.7°C).Humidity
In September, the average relative humidity in Cle Elum is 68%.Rainfall
In September, the rain falls for 10.7 days. Throughout September, 1.1" (28mm) of precipitation is accumulated. Throughout the year, in Cle Elum, there are 161.2 rainfall days, and 28.46" (723mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, September through December. September is the first month it typically snows in Cle Elum. Throughout September, in the average 0.2 snowfall days, it receives 0.2" (5mm) of snow. In Cle Elum, during the entire year, snow falls for 69.9 days and aggregates up to 60.24" (1530mm) of snow.Daylight
The average length of the day in September in Cle Elum is 12h and 32min.On the first day of the month, sunrise is at 6:24 am and sunset at 7:42 pm. On the last day of September, in Cle Elum, sunrise is at 7:02 am and sunset at 6:44 pm PDT.
Sunshine
In Cle Elum, Washington, the average sunshine in September is 10.2h.UV index
In September, the average daily maximum UV index in Cle Elum is 3. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for the average person.Note: An average maximum UV index of 3 in September leads to these recommendations:
Take care. Persons with lighter skin might suffer burns in less than 30 minutes. To guard against the harmful effects of the Sun, minimize exposure during midday. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat. Beware! Reflection from snow can magnify the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Cle Elum, WA
- Average high temperature in September: 64.6°F
The warmest month (with the highest average high temperature) is August (75.4°F).
The month with the lowest average high temperature is December (29.7°F).
- Average low temperature in September: 42.3°F
The month with the highest average low temperature is August (47.8°F).
The coldest month (with the lowest average low temperature) is December (18.3°F).
Average pressure in September
Cle Elum, WA
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is August (29.96"Hg).
Average wind speed in September
Cle Elum, WA
- Average wind speed in September: 5.3mph
The windiest month (with the highest average wind speed) is June (6.7mph).
The calmest month (with the lowest average wind speed) is December (4.2mph).
Average humidity in September
Cle Elum, WA
- Average humidity in September: 68%
The months with the highest relative humidity are January and February (92%).
The months with the lowest relative humidity are July and August (60%).
Average rainfall in September
Cle Elum, WA
- Average rainfall in September: 1.1"
The wettest month (with the highest rainfall) is January (4.41").
The driest month (with the least rainfall) is July (0.39").
Average rainfall days in September
Cle Elum, WA
- Average rainfall days in September: 10.7 days
The months with the highest number of rainy days are March and April (18.3 days).
The month with the least rainy days is August (5.5 days).
Average snowfall in September
Cle Elum, WA
- Average snowfall in September: 0.2"
The month with the highest snowfall is January (16.3").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Cle Elum, WA
- Average snowfall days in September: 0.2 days
The month with the highest number of snowfall days is December (15.1 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Cle Elum, WA
- Average daylight in September: 12h and 30min
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: 10h and 12min
The month with the most sunshine is August (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 24min).
Average sunshine days in September
Cle Elum, WA
- Average sunshine days in September: 16.3 days
The month with the most sunshine days is August (22.8 days).
The month with the least sunshine days is February (6.8 days).
Average UV index in September
Cle Elum, 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, November and December (UV index 1).
Average cloud cover in September
Cle Elum, WA
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 63).
The months with the least cloud cover are July and August (Cloud cover 18).
Average visibility in September
Cle Elum, WA
- Average visibility in September: 6mi
The months with the highest visibility are May, June, July, August and September (6mi).
The month with the lowest visibility is January (3mi).





