September weather forecastTacoma, WA
September
Weather in September
As September rolls in, a perceptible shift in Tacoma's weather indicates the onset of fall. Temperatures begin to scale back, with highs at about 70.9°F (21.6°C). The rainfall rashly jumps up to 1.54" (39mm), washing over the city to reveal bright autumn hues. It's a pivot point where summer activities make room for fall traditions. The city's scenery transforms, paving the way for a new spectrum of experiences among the residents.Temperature
The onset of September results in a small decrease in the average high-temperature, moderately receding from a moderately hot 78.1°F (25.6°C) in August to an agreeable 70.9°F (21.6°C). In Tacoma, an average temperature of 49.5°F (9.7°C) is noted during September nights.Humidity
In Tacoma, the average relative humidity in September is 75%.Rainfall
In Tacoma, in September, it is raining for 11.9 days, with typically 1.54" (39mm) of accumulated precipitation. Throughout the year, there are 172.9 rainfall days, and 30.08" (764mm) of precipitation is accumulated.Snowfall
April through October are months without snowfall.Ocean temperature
In September, the average ocean temperature is 53.4°F (11.9°C).Note: Without suitable protection, venturing into 53.4°F (11.9°C) waters cooler than 50°F (10°C) can lead to pronounced cold shock and rapid breaths.
Daylight
The average length of the day in September is 12h and 32min.On the first day of the month, sunrise is at 6:30 am and sunset at 7:49 pm. On the last day of September, sunrise is at 7:08 am and sunset at 6:50 pm PDT.
Sunshine
The average sunshine in September is 9h.UV index
In Tacoma, 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 ordinary individuals.Note: In September, the average maximum UV index of 4 translates into the following recommendations:
Exercise prevention - Warding off sunburn is urged. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Tacoma, 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
Tacoma, 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
Tacoma, 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
Tacoma, 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
Tacoma, 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
Tacoma, 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
Tacoma, 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
Tacoma, 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 sea temperature in September
Tacoma, WA
- Average sea temperature in September: 53.5°F
The best month for swimming (with the highest average sea temperature) is August (53.7°F).
The coldest month (with the lowest average sea temperature) is February (45.8°F).
Average daylight in September /
Average sunshine in September
Tacoma, WA
- Average daylight in September: 12h and 30min
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
Tacoma, 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
Tacoma, 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
Tacoma, 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
Tacoma, 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).
