September weather forecastHolmes, WA
September
Weather in September
September, the first month of the autumn in Holmes, is also an agreeable month, with an average temperature varying between 49.1°F (9.5°C) and 71.1°F (21.7°C).Temperature
The beginning of September marks a decrease in the average high-temperature, transitioning from a warm 82°F (27.8°C) in August to a pleasant 71.1°F (21.7°C). Throughout the month of September, Holmes observes a dramatic downturn from the daytime peak temperatures, expecting an average low of 49.1°F (9.5°C).Humidity
The average relative humidity in September is 54%.Rainfall
In Holmes, in September, during 6.1 rainfall days, 0.47" (12mm) of precipitation is typically accumulated. In Holmes, during the entire year, the rain falls for 99.9 days and collects up to 8.66" (220mm) of precipitation.Snowfall
Months with snowfall in Holmes are January through April, September through December. September is the first month it typically snows in Holmes, Washington. Throughout September, in the average 0.3 snowfall days, it receives 0.31" (8mm) of snow. Throughout the year, there are 35.4 snowfall days, and 15.59" (396mm) of snow is accumulated.Daylight
In September, the average length of the day in Holmes is 12h and 32min.On the first day of the month, sunrise is at 6:22 am and sunset at 7:40 pm. On the last day of September, in Holmes, sunrise is at 7:00 am and sunset at 6:42 pm PDT.
Sunshine
The average sunshine in September is 10.7h.UV index
In Holmes, Washington, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for the average person.Note: A typical high UV index of 4 in September suggests the following recommendations:
Undertake precautions - Guarding against sun damage is counselled. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades. Guard yourself! Snow reflection can almost double the UV radiation from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Holmes, WA
- Average high temperature in September: 71.1°F
The warmest months (with the highest average high temperature) are July and August (82°F).
The month with the lowest average high temperature is December (33.3°F).
- Average low temperature in September: 49.1°F
The month with the highest average low temperature is August (55.2°F).
The coldest month (with the lowest average low temperature) is December (21.4°F).
Average pressure in September
Holmes, WA
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is August (29.94"Hg).
Average wind speed in September
Holmes, WA
- Average wind speed in September: 6.9mph
The windiest month (with the highest average wind speed) is June (8.9mph).
The calmest month (with the lowest average wind speed) is December (4.2mph).
Average humidity in September
Holmes, WA
- Average humidity in September: 54%
The month with the highest relative humidity is January (87%).
The months with the lowest relative humidity are July and August (46%).
Average rainfall in September
Holmes, WA
- Average rainfall in September: 0.47"
The wettest month (with the highest rainfall) is December (1.3").
The driest month (with the least rainfall) is July (0.16").
Average rainfall days in September
Holmes, WA
- Average rainfall days in September: 6.1 days
The month with the highest number of rainy days is March (12.4 days).
The month with the least rainy days is August (2.8 days).
Average snowfall in September
Holmes, WA
- Average snowfall in September: 0.31"
The month with the highest snowfall is December (4.65").
The months with the least snowfall are May, June, July and August (0").
Average snowfall days in September
Holmes, WA
- Average snowfall days in September: 0.3 days
The months with the highest number of snowfall days are January and December (8.7 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Holmes, WA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 48min).
The month with the shortest days is December (Average daylight: 8h and 36min).
- Average sunshine in September: 10h and 42min
The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The months with the least sunshine are January and December (Average sunshine: 4h and 48min).
Average sunshine days in September
Holmes, WA
- Average sunshine days in September: 22.8 days
The month with the most sunshine days is July (27.1 days).
The month with the least sunshine days is February (13.5 days).
Average UV index in September
Holmes, 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, March, November and December (UV index 2).
Average cloud cover in September
Holmes, WA
- Average cloud cover in September: 18
The month with the most cloud cover is January (Cloud cover 48).
The months with the least cloud cover are July and August (Cloud cover 11).
Average visibility in September
Holmes, 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).





