September weather forecastHillside Siding, WA
September
Weather in September
September, the first month of the autumn in Hillside Siding, is also a moderately hot month, with an average temperature varying between 51.8°F (11°C) and 74.1°F (23.4°C).Temperature
The shift from August to September involves a decrease in the average high-temperature, from a moderately hot 85.1°F (29.5°C) to a still warm 74.1°F (23.4°C). Hillside Siding experiences a significant reduction from daytime highs with an average low-temperature of 51.8°F (11°C) in September.Humidity
In September, the average relative humidity is 50%.Rainfall
In Hillside Siding, in September, it is raining for 4.8 days, with typically 0.28" (7mm) of accumulated precipitation. In Hillside Siding, during the entire year, the rain falls for 87.6 days and collects up to 5.94" (151mm) of precipitation.Snowfall
January through April, September, November and December are months with snowfall. September is the first month it typically snows in Hillside Siding. Throughout September, in the average 0.1 snowfall days, it receives 0.12" (3mm) of snow. Throughout the year, there are 19.9 snowfall days, and 8.62" (219mm) of snow is accumulated.Daylight
In Hillside Siding, the average length of the day in September is 12h and 32min.On the first day of September, sunrise is at 6:22 am and sunset at 7:40 pm. On the last day of the month, sunrise is at 7:00 am and sunset at 6:42 pm PDT.
Sunshine
In Hillside Siding, the average sunshine in September is 11.1h.UV index
In Hillside Siding, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for the average person.Note: The maximum UV index of 4 during September leads to these instructions:
Guard yourself - Avoiding sunburn is suggested. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly. Take into account! The reflection from snow can nearly double the Sun's UV radiation intensity.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Hillside Siding, WA
- Average high temperature in September: 74.1°F
The warmest month (with the highest average high temperature) is August (85.1°F).
The month with the lowest average high temperature is December (36°F).
- Average low temperature in September: 51.8°F
The month with the highest average low temperature is August (58.8°F).
The coldest month (with the lowest average low temperature) is December (23.9°F).
Average pressure in September
Hillside Siding, 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 (29.93"Hg).
Average wind speed in September
Hillside Siding, WA
- Average wind speed in September: 6.1mph
The windiest month (with the highest average wind speed) is June (7.4mph).
The calmest month (with the lowest average wind speed) is December (4.2mph).
Average humidity in September
Hillside Siding, WA
- Average humidity in September: 50%
The month with the highest relative humidity is January (83%).
The months with the lowest relative humidity are July and August (41%).
Average rainfall in September
Hillside Siding, WA
- Average rainfall in September: 0.28"
The wettest month (with the highest rainfall) is December (0.87").
The driest month (with the least rainfall) is July (0.08").
Average rainfall days in September
Hillside Siding, WA
- Average rainfall days in September: 4.8 days
The month with the highest number of rainy days is March (10.8 days).
The month with the least rainy days is July (2.3 days).
Average snowfall in September
Hillside Siding, WA
- Average snowfall in September: 0.12"
The month with the highest snowfall is December (3.07").
The months with the least snowfall are May, June, July, August and October (0").
Average snowfall days in September
Hillside Siding, WA
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is December (5.7 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
Hillside Siding, 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: 11h and 6min
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 30min).
Average sunshine days in September
Hillside Siding, WA
- Average sunshine days in September: 23.2 days
The month with the most sunshine days is July (27.6 days).
The month with the least sunshine days is February (15.5 days).
Average UV index in September
Hillside Siding, 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
Hillside Siding, WA
- Average cloud cover in September: 15
The month with the most cloud cover is January (Cloud cover 40).
The months with the least cloud cover are July and August (Cloud cover 9).
Average visibility in September
Hillside Siding, WA
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).





