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
The transition into September shows a subtle variation to a refreshing 67.8°F (19.9°C) from August's 71.4°F (21.9°C) in the average high-temperature. Cosmopolis, in September, witnesses an average low-temperature of 49.5°F (9.7°C).Humidity
In September, the average relative humidity is 82%.Rainfall
In Cosmopolis, in September, during 8.4 rainfall days, 0.47" (12mm) of precipitation is typically accumulated. In Cosmopolis, during the entire year, the rain falls for 113.5 days and collects up to 10.24" (260mm) of precipitation.Snowfall
In Cosmopolis, snow does not fall in April through December.Daylight
In September, the average length of the day is 12h and 32min.On the first day of September, sunrise is at 6:35 am and sunset at 7:53 pm. On the last day of the month, sunrise is at 7:13 am and sunset at 6:55 pm PDT.
Sunshine
In Cosmopolis, the average sunshine in September is 8.2h.UV index
In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for the average person.Note: In September, a daily maximum UV index of 4 leads to the following instructions:
Take care. Persons with lighter skin might suffer burns in less than 30 minutes. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
How many hours of daylight does Cosmopolis have in September?
What time are sunrise and sunset in September in Cosmopolis?
How long on average sun shines in September?
What is the UV index intensity in September?
Average temperature in September
Cosmopolis, WA
- Average high temperature in September: 67.8°F
The warmest month (with the highest average high temperature) is August (71.4°F).
The month with the lowest average high temperature is December (44.2°F).
- Average low temperature in September: 49.5°F
The month with the highest average low temperature is August (51.1°F).
The coldest month (with the lowest average low temperature) is December (36.5°F).
Average pressure in September
Cosmopolis, WA
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is July (30.08"Hg).
The month with the lowest atmospheric pressure is March (30.01"Hg).
Average wind speed in September
Cosmopolis, WA
- Average wind speed in September: 4.7mph
The windiest month (with the highest average wind speed) is January (7mph).
The calmest month (with the lowest average wind speed) is September (4.7mph).
Average humidity in September
Cosmopolis, WA
- Average humidity in September: 82%
The months with the highest relative humidity are November and December (88%).
The month with the lowest relative humidity is July (78%).
Average rainfall in September
Cosmopolis, WA
- Average rainfall in September: 0.47"
The wettest month (with the highest rainfall) is January (1.93").
The driest months (with the least rainfall) are July and August (0.12").
Average rainfall days in September
Cosmopolis, WA
- Average rainfall days in September: 8.4 days
The month with the highest number of rainy days is March (13.6 days).
The month with the least rainy days is August (3.2 days).
Average snowfall in September
Cosmopolis, WA
- Average snowfall in September: 0"
The months with the highest snowfall are January and February (0.28").
The months with the least snowfall are April, May, June, July, August, September, October, November and December (0").
Average snowfall days in September
Cosmopolis, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (1.3 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Cosmopolis, WA
- Average daylight in September: 12h and 3min
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: 8h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 24min).
Average sunshine days in September
Cosmopolis, WA
- Average sunshine days in September: 20.2 days
The month with the most sunshine days is August (25.4 days).
The months with the least sunshine days are February and March (14.1 days).
Average UV index in September
Cosmopolis, WA
- Average UV index in September: 4
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 2).
Average cloud cover in September
Cosmopolis, WA
- Average cloud cover in September: 44
The month with the most cloud cover is January (Cloud cover 64).
The month with the least cloud cover is July (Cloud cover 37).
Average visibility in September
Cosmopolis, WA
- Average visibility in September: 4mi
The months with the highest visibility are February, March, April, May, June and November (5mi).
The months with the lowest visibility are January, July, August, September, October and December (4mi).
Cosmopolis, Washington, USA
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