September weather forecastOso, WA
September
Weather in September
The first month of the autumn, September, is also an enjoyable month in Oso, Washington, with an average temperature fluctuating between 66.2°F (19°C) and 49.1°F (9.5°C).Temperature
The onset of September results in a small decrease in the average high-temperature, moderately receding from a pleasant 72.3°F (22.4°C) in August to a refreshing 66.2°F (19°C). Oso in September anticipates an average nighttime temperature of 49.1°F (9.5°C).Humidity
In September, the average relative humidity in Oso, Washington, is 78%.Rainfall
In Oso, Washington, during September, the rain falls for 13.5 days and regularly aggregates up to 2.05" (52mm) of precipitation. Throughout the year, in Oso, Washington, there are 188.6 rainfall days, and 34.92" (887mm) of precipitation is accumulated.Snowfall
In Oso, snow does not fall in May through October.Daylight
In Oso, the average length of the day in September is 12h and 34min.On the first day of the month, sunrise is at 6:26 am and sunset at 7:48 pm. On the last day of September, sunrise is at 7:06 am and sunset at 6:48 pm PDT.
Sunshine
In Oso, the average sunshine in September is 9.2h.UV index
The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV radiation for the ordinary person.Note: In September, an average UV index of 4 transforms into the following instructions:
Preventative actions are necessary - The mandate to avoid skin and eye damage is in place. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Oso, 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
Oso, 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
Oso, 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
Oso, 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
Oso, 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
Oso, 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
Oso, 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
Oso, 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
Oso, WA
- Average daylight in September: 12h and 36min
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 12min
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
Oso, 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
Oso, 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
Oso, 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
Oso, 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).
