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 sea temperature 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 start of September comes with a small reduction in the average high-temperature, subtly receding from a moderately hot 77.9°F (25.5°C) in August to a pleasant 70.7°F (21.5°C). Longview anticipates a considerable daily temperature fluctuation in September, with low temperatures averaging a frosty 47.3°F (8.5°C).Humidity
In September, the average relative humidity is 78%.Rainfall
In September, the rain falls for 10.8 days. Throughout September, 1.26" (32mm) of precipitation is accumulated. Throughout the year, in Longview, there are 175.5 rainfall days, and 25.83" (656mm) of precipitation is accumulated.Snowfall
April through October are months without snowfall.Ocean temperature
With an average ocean temperature of 53.8°F (12.1°C), September is the month with the warmest seawater.Note: To swim in 53.8°F (12.1°C) at less than 50°F (10°C), ensure you're well-protected. Without it, be prepared for a sudden jolt of cold and breathing issues. Remember, even 55.4°F (13°C) is not welcoming.
Daylight
In Longview, the average length of the day in September is 12h and 31min.On the first day of the month, sunrise is at 6:33 am and sunset at 7:49 pm. On the last day of September, sunrise is at 7:10 am and sunset at 6:52 pm PDT.
Sunshine
In Longview, the average sunshine in September is 8.4h.UV index
In September, the average daily maximum UV index in Longview is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for ordinary individuals.Note: The maximum UV index, 4 during September, leads to the following recommendations:
Undertake precautions - Obligation exists to protect against skin and eye damage. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Longview in September?
What is the average humidity in September in Longview?
How many days does it rain in September in Longview?
When it does not snow in Longview?
What is the month with the warmest ocean in Longview?
How cold is the water in September in Longview?
How many hours of daylight does Longview have in September?
When are sunrise and sunset in September in Longview?
How long on average sun shines in September in Longview?
How high is the UV index in September in Longview?
Average temperature in September
Longview, WA
- Average high temperature in September: 70.7°F
The warmest month (with the highest average high temperature) is August (77.9°F).
The month with the lowest average high temperature is December (42.3°F).
- Average low temperature in September: 47.3°F
The month with the highest average low temperature is August (49.8°F).
The coldest month (with the lowest average low temperature) is December (32.7°F).
Average pressure in September
Longview, WA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The months with the lowest atmospheric pressure are August and September (30.01"Hg).
Average wind speed in September
Longview, WA
- Average wind speed in September: 3.9mph
The windiest month (with the highest average wind speed) is January (4.8mph).
The calmest month (with the lowest average wind speed) is September (3.9mph).
Average humidity in September
Longview, WA
- Average humidity in September: 78%
The months with the highest relative humidity are January, February, November and December (88%).
The month with the lowest relative humidity is July (72%).
Average rainfall in September
Longview, WA
- Average rainfall in September: 1.26"
The wettest month (with the highest rainfall) is January (3.9").
The driest month (with the least rainfall) is August (0.39").
Average rainfall days in September
Longview, WA
- Average rainfall days in September: 10.8 days
The month with the highest number of rainy days is March (20.3 days).
The month with the least rainy days is July (6.1 days).
Average snowfall in September
Longview, WA
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.26").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Longview, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.2 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average sea temperature in September
Longview, WA
- Average sea temperature in September: 53.8°F
The best month for swimming (with the highest average sea temperature) is September (53.8°F).
The coldest month (with the lowest average sea temperature) is February (46.6°F).
Average daylight in September /
Average sunshine in September
Longview, WA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in September: 8h and 2min
The month with the most sunshine is August (Average sunshine: 10h and 24min).
The months with the least sunshine are January, February and December (Average sunshine: 3h and 30min).
Average sunshine days in September
Longview, WA
- Average sunshine days in September: 17 days
The month with the most sunshine days is July (22 days).
The month with the least sunshine days is March (8.9 days).
Average UV index in September
Longview, WA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 5).
The month with the lowest UV index is November (UV index 1).
Average cloud cover in September
Longview, WA
- Average cloud cover in September: 44
The months with the most cloud cover are February and March (Cloud cover 65).
The month with the least cloud cover is August (Cloud cover 36).
Average visibility in September
Longview, WA
- Average visibility in September: 4mi
The month with the highest visibility is August (5mi).
The months with the lowest visibility are January, February, March, April, May, June, July, September, October, November and December (4mi).
Longview, Washington, USA
Weather forecast for your location
2. Allow the app to use your location