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
In September, the average high-temperature is essentially the same as in August - a still warm 76.1°F (24.5°C). The average low-temperature, in September, is 57.2°F (14°C).Humidity
The average relative humidity in September is 76%.Rainfall
In Washington, in September, during 11.2 rainfall days, 1.57" (40mm) of precipitation is typically accumulated. In Washington, during the entire year, the rain falls for 128.3 days and collects up to 19.13" (486mm) of precipitation.Snowfall
In Washington, snow does not fall in May through October.Daylight
The average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:24 am and sunset at 7:30 pm. On the last day of September, sunrise is at 6:53 am and sunset at 6:42 pm CDT.
Sunshine
The average sunshine in September is 9.2h.UV index
The average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for ordinary individuals.Note: The average daily UV index of 5 in September transform into the following instructions:
Take precautions - Protection against sun damage is advised. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.
FAQ
What is the temperature in September in Washington?
What is the average humidity in September in Washington?
How much does it rain in Washington in September?
When it does not snow in Washington?
How many hours of daylight does Washington have in September?
When is the sunrise / sunset in September in Washington?
How many hours of sunshine does Washington have in September?
What is the UV index reading in September in Washington?
Average temperature in September
Washington, IL
- Average high temperature in September: 76.1°F
The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (30.6°F).
- Average low temperature in September: 57.2°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (18.5°F).
Average pressure in September
Washington, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Washington, IL
- Average wind speed in September: 7.6mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity in September
Washington, IL
- Average humidity in September: 76%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Washington, IL
- Average rainfall in September: 1.57"
The wettest month (with the highest rainfall) is May (2.6").
The driest month (with the least rainfall) is November (0.94").
Average rainfall days in September
Washington, IL
- Average rainfall days in September: 11.2 days
The month with the highest number of rainy days is July (16.4 days).
The month with the least rainy days is January (4.4 days).
Average snowfall in September
Washington, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.68").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Washington, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (10.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Washington, IL
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is June (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in September
Washington, IL
- Average sunshine days in September: 17.2 days
The month with the most sunshine days is December (20.5 days).
The month with the least sunshine days is July (11.4 days).
Average UV index in September
Washington, IL
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Washington, IL
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is September (Cloud cover 30).
Average visibility in September
Washington, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
Weather forecast for your location
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