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
Onset of September comes with a temperature decline, the average high falling from a tropical 86.9°F (30.5°C) in August to a moderately hot 75.9°F (24.4°C). During September nights, Cascade Valley witnesses a consistent average temperature of 55.2°F (12.9°C).Humidity
The average relative humidity in September is 44%.Rainfall
In Cascade Valley, in September, it is raining for 5.4 days, with typically 0.31" (8mm) of accumulated precipitation. In Cascade Valley, during the entire year, the rain falls for 103.1 days and collects up to 7.8" (198mm) of precipitation.Snowfall
January through April, September, November and December are months with snowfall. September is the first month it typically snows in Cascade Valley. Throughout September, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow. In Cascade Valley, during the entire year, snow falls for 20.9 days and aggregates up to 8.07" (205mm) of snow.Daylight
In Cascade Valley, the average length of the day in September is 12h and 32min.On the first day of the month, sunrise is at 6:17 am and sunset at 7:36 pm. On the last day of September, sunrise is at 6:55 am and sunset at 6:38 pm PDT.
Sunshine
In Cascade Valley, the average sunshine in September is 10.8h.UV index
In Cascade Valley, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for the average person.Note: A daily high UV index of 4 in September leads to these guidelines:
Take care. Persons with lighter skin might suffer burns in less than 30 minutes. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage. Be mindful! The reflection from snow can increase the Sun's UV radiation nearly twice.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
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 in Cascade Valley?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Cascade Valley, WA
- Average high temperature in September: 75.9°F
The warmest month (with the highest average high temperature) is July (87.6°F).
The month with the lowest average high temperature is December (34°F).
- Average low temperature in September: 55.2°F
The month with the highest average low temperature is August (62.2°F).
The coldest month (with the lowest average low temperature) is December (23.9°F).
Average pressure in September
Cascade Valley, WA
- Average pressure in September: 29.95"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).
Average wind speed in September
Cascade Valley, WA
- Average wind speed in September: 6.3mph
The windiest month (with the highest average wind speed) is April (7.9mph).
The calmest months (with the lowest average wind speed) are January and December (5.5mph).
Average humidity in September
Cascade Valley, WA
- Average humidity in September: 44%
The month with the highest relative humidity is January (85%).
The months with the lowest relative humidity are July and August (36%).
Average rainfall in September
Cascade Valley, WA
- Average rainfall in September: 0.31"
The wettest month (with the highest rainfall) is January (1.02").
The driest month (with the least rainfall) is August (0.2").
Average rainfall days in September
Cascade Valley, WA
- Average rainfall days in September: 5.4 days
The month with the highest number of rainy days is March (12.8 days).
The month with the least rainy days is July (3.8 days).
Average snowfall in September
Cascade Valley, WA
- Average snowfall in September: 0.04"
The month with the highest snowfall is December (2.6").
The months with the least snowfall are May, June, July, August and October (0").
Average snowfall days in September
Cascade Valley, WA
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is December (6.8 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
Cascade Valley, WA
- Average daylight in September: 12h and 3min
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 5min
The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 54min).
Average sunshine days in September
Cascade Valley, WA
- Average sunshine days in September: 23.4 days
The month with the most sunshine days is July (25.8 days).
The month with the least sunshine days is March (14.2 days).
Average UV index in September
Cascade Valley, WA
- Average UV index in September: 4
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Cascade Valley, WA
- Average cloud cover in September: 16
The month with the most cloud cover is January (Cloud cover 49).
The months with the least cloud cover are July and August (Cloud cover 11).
Average visibility in September
Cascade Valley, 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).
Cascade Valley, Washington, USA
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