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 brings a decrease in the average high-temperature, falling from August's hot 89.4°F (31.9°C) to a warm 78.6°F (25.9°C). In West Richland, an average temperature of 57°F (13.9°C) is noted during September nights.Humidity
In West Richland, the average relative humidity in September is 43%.Rainfall
The months with the least rainfall are July and September Rain falls for 4 days and accumulates 0.2" (5mm) of rain.Snowfall
In West Richland, snow does not fall in April through October.Daylight
In West Richland, Washington, the average length of the day in September is 12h and 32min.On the first day of the month, sunrise is at 6:18 am and sunset at 7:35 pm. On the last day of September, sunrise is at 6:55 am and sunset at 6:38 pm PDT.
Sunshine
In West Richland, the average sunshine in September is 10.9h.UV index
In West Richland, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for the average person.Note: A maximum UV index of 5 in September translates into the following recommendations:
Take precautions - Protection against sunburn is recommended. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for West Richland in September?
What is the average humidity in September?
What is the driest month?
How much does it rain in September?
When it does not snow?
How many hours of daylight does West Richland have in September?
What time are sunrise and sunset in September?
How many hours of sunshine does West Richland have in September?
What is the UV index reading in September in West Richland?
Average temperature in September
West Richland, WA
- Average high temperature in September: 78.6°F
The warmest month (with the highest average high temperature) is July (90.1°F).
The month with the lowest average high temperature is December (38.1°F).
- Average low temperature in September: 57°F
The month with the highest average low temperature is August (64.2°F).
The coldest month (with the lowest average low temperature) is December (27.5°F).
Average pressure in September
West Richland, WA
- Average pressure in September: 29.95"Hg
The month with the highest atmospheric pressure is January (30.18"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).
Average wind speed in September
West Richland, WA
- Average wind speed in September: 6.6mph
The windiest month (with the highest average wind speed) is April (8.3mph).
The calmest month (with the lowest average wind speed) is December (5.6mph).
Average humidity in September
West Richland, WA
- Average humidity in September: 43%
The month with the highest relative humidity is January (81%).
The month with the lowest relative humidity is July (35%).
Average rainfall in September
West Richland, WA
- Average rainfall in September: 0.2"
The wettest month (with the highest rainfall) is December (0.94").
The driest months (with the least rainfall) are July and September (0.2").
Average rainfall days in September
West Richland, WA
- Average rainfall days in September: 4 days
The month with the highest number of rainy days is March (12.3 days).
The month with the least rainy days is July (3.5 days).
Average snowfall in September
West Richland, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (2.2").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
West Richland, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is December (3.3 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
West Richland, 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: 10h and 5min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 5h and 24min).
Average sunshine days in September
West Richland, WA
- Average sunshine days in September: 24.2 days
The month with the most sunshine days is July (25.7 days).
The months with the least sunshine days are February and March (15.3 days).
Average UV index in September
West Richland, WA
- Average UV index in September: 5
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
West Richland, WA
- Average cloud cover in September: 16
The month with the most cloud cover is January (Cloud cover 44).
The month with the least cloud cover is July (Cloud cover 9).
Average visibility in September
West Richland, WA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
West Richland, Washington, USA
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