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 shift from August to September coincides with a small decrease in the average high-temperature, down to a comfortable 66.2°F (19°C) from a pleasant 72.3°F (22.4°C). In Arlington, the expected average low-temperature for September is a chilly 49.1°F (9.5°C).Humidity
In Arlington, the average relative humidity in September is 78%.Rainfall
In Arlington, in September, it is raining for 13.5 days, with typically 2.05" (52mm) of accumulated precipitation. In Arlington, during the entire year, the rain falls for 188.6 days and collects up to 34.92" (887mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
The average length of the day in September is 12h and 34min.On the first day of the month, sunrise is at 6:27 am and sunset at 7:48 pm. On the last day of September, sunrise is at 7:07 am and sunset at 6:48 pm PDT.
Sunshine
In September, the average sunshine is 9.2h.UV index
In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for the ordinary person.Note: The daily high UV index of 4 in September translates into this advice:
Take necessary precautions - Protection from skin and eye injury is mandatory. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
What is the average length of the day in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
Arlington, WA
- Average high temperature in September: 66.2°F
The warmest month (with the highest average high temperature) is August (72.3°F).
The month with the lowest average high temperature is December (41.7°F).
- Average low temperature in September: 49.1°F
The month with the highest average low temperature is August (51.6°F).
The coldest month (with the lowest average low temperature) is February (33.8°F).
Average pressure in September
Arlington, WA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.09"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).
Average wind speed in September
Arlington, WA
- Average wind speed in September: 3.9mph
The windiest months (with the highest average wind speed) are January and November (5.6mph).
The calmest month (with the lowest average wind speed) is August (3.3mph).
Average humidity in September
Arlington, WA
- Average humidity in September: 78%
The months with the highest relative humidity are January, February, November and December (85%).
The month with the lowest relative humidity is July (73%).
Average rainfall in September
Arlington, WA
- Average rainfall in September: 2.05"
The wettest month (with the highest rainfall) is November (4.92").
The driest month (with the least rainfall) is July (0.51").
Average rainfall days in September
Arlington, WA
- Average rainfall days in September: 13.5 days
The month with the highest number of rainy days is March (20.9 days).
The month with the least rainy days is August (6.9 days).
Average snowfall in September
Arlington, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (4.45").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Arlington, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (4.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Arlington, WA
- Average daylight in September: 12h and 4min
The month with the longest days is June (Average daylight: 16h and 0min).
The month with the shortest days is December (Average daylight: 8h and 24min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 4h and 6min).
Average sunshine days in September
Arlington, WA
- Average sunshine days in September: 15.2 days
The month with the most sunshine days is August (22 days).
The month with the least sunshine days is March (8.1 days).
Average UV index in September
Arlington, 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, October, November and December (UV index 2).
Average cloud cover in September
Arlington, WA
- Average cloud cover in September: 34
The month with the most cloud cover is December (Cloud cover 57).
The months with the least cloud cover are July and August (Cloud cover 26).
Average visibility in September
Arlington, WA
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September and October (6mi).
The months with the lowest visibility are January, February, November and December (5mi).
Arlington, Washington, USA
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