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
September is characterized by a mild reduction in the average high-temperature, from a moderately hot 78.1°F (25.6°C) in August to a pleasant 70.9°F (21.6°C). Steilacoom, in September, witnesses an average low-temperature of 49.5°F (9.7°C).Humidity
In Steilacoom, the average relative humidity in September is 75%.Rainfall
In September, in Steilacoom, the rain falls for 11.9 days. Throughout September, 1.54" (39mm) of precipitation is accumulated. In Steilacoom, during the entire year, the rain falls for 172.9 days and collects up to 30.08" (764mm) of precipitation.Snowfall
April through October are months without snowfall in Steilacoom.Daylight
The average length of the day in September in Steilacoom is 12h and 32min.On the first day of September, sunrise is at 6:30 am and sunset at 7:49 pm. On the last day of the month, sunrise is at 7:09 am and sunset at 6:51 pm PDT.
Sunshine
In Steilacoom, the average sunshine in September is 9h.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 average individuals.Note: The maximum UV index of 4 during September translates into these guidelines:
Take necessary precautions - Defending against sun damage is advocated. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear.
Frequently asked questions
What are September temperatures in Steilacoom?
What is the average humidity in September in Steilacoom?
How many days does it rain in September in Steilacoom?
When it does not snow in Steilacoom?
What is the average length of the day in September in Steilacoom?
When is the sunrise / sunset in September in Steilacoom?
How many hours of sunshine does Steilacoom have in September?
What is the UV index intensity in September in Steilacoom?
Average temperature in September
Steilacoom, WA
- Average high temperature in September: 70.9°F
The warmest month (with the highest average high temperature) is August (78.1°F).
The month with the lowest average high temperature is December (43.7°F).
- Average low temperature in September: 49.5°F
The month with the highest average low temperature is August (52.7°F).
The coldest months (with the lowest average low temperature) are February and December (34.3°F).
Average pressure in September
Steilacoom, WA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.09"Hg).
The months with the lowest atmospheric pressure are March, August and September (30.01"Hg).
Average wind speed in September
Steilacoom, WA
- Average wind speed in September: 4mph
The windiest month (with the highest average wind speed) is March (5.2mph).
The calmest month (with the lowest average wind speed) is August (3.7mph).
Average humidity in September
Steilacoom, WA
- Average humidity in September: 75%
The months with the highest relative humidity are January and December (87%).
The month with the lowest relative humidity is July (68%).
Average rainfall in September
Steilacoom, WA
- Average rainfall in September: 1.54"
The wettest month (with the highest rainfall) is December (4.69").
The driest month (with the least rainfall) is July (0.39").
Average rainfall days in September
Steilacoom, WA
- Average rainfall days in September: 11.9 days
The month with the highest number of rainy days is March (20.1 days).
The month with the least rainy days is August (5 days).
Average snowfall in September
Steilacoom, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (2.28").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Steilacoom, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (3.2 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
Steilacoom, 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: 9h and 0min
The month with the most sunshine is August (Average sunshine: 10h and 36min).
The month with the least sunshine is December (Average sunshine: 4h and 0min).
Average sunshine days in September
Steilacoom, WA
- Average sunshine days in September: 16.5 days
The month with the most sunshine days is August (23.4 days).
The month with the least sunshine days is February (9 days).
Average UV index in September
Steilacoom, 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
Steilacoom, WA
- Average cloud cover in September: 36
The month with the most cloud cover is December (Cloud cover 59).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in September
Steilacoom, WA
- Average visibility in September: 5mi
The months with the highest visibility are June, July and August (6mi).
The months with the lowest visibility are January, February, March, April, May, September, October, November and December (5mi).
Steilacoom, Washington, USA
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