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
During September, Downs observes a subtle ascent to a still moderately hot 75.9°F (24.4°C) from August's 79.9°F (26.6°C) in the average high-temperature. Downs experiences a mean temperature of 57.9°F (14.4°C) during September nights.Humidity
In September, the average relative humidity is 76%.Rainfall
In Downs, in September, during 11.6 rainfall days, 1.38" (35mm) of precipitation is typically accumulated. Throughout the year, there are 139 rainfall days, and 20.83" (529mm) of precipitation is accumulated.Snowfall
May through October are months without snowfall in Downs.Daylight
In Downs, the average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:23 am and sunset at 7:26 pm. On the last day of September, in Downs, sunrise is at 6:51 am and sunset at 6:38 pm CDT.
Sunshine
In Downs, the average sunshine in September is 9h.UV index
The average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for average individuals.Note: An average maximum UV index of 5 in September leads to these recommendations:
Adopt protective measures - Requirement to safeguard skin and eyes from harm exists. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
How many hours of daylight does Downs have in September?
When are sunrise and sunset in September?
How many hours of sunshine does Downs have in September?
What is the UV index reading in September?
Average temperature in September
Downs, IL
- Average high temperature in September: 75.9°F
The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is January (31.3°F).
- Average low temperature in September: 57.9°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 (19.6°F).
Average pressure in September
Downs, 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 (29.92"Hg).
Average wind speed in September
Downs, IL
- Average wind speed in September: 7.6mph
The windiest month (with the highest average wind speed) is January (11mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity in September
Downs, IL
- Average humidity in September: 76%
The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Downs, IL
- Average rainfall in September: 1.38"
The wettest month (with the highest rainfall) is May (2.87").
The driest month (with the least rainfall) is December (1.1").
Average rainfall days in September
Downs, IL
- Average rainfall days in September: 11.6 days
The month with the highest number of rainy days is May (17.5 days).
The month with the least rainy days is January (5.8 days).
Average snowfall in September
Downs, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.8").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Downs, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (9.8 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
Downs, IL
- Average daylight in September: 12h and 2min
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 0min
The month with the most sunshine is June (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in September
Downs, IL
- Average sunshine days in September: 16.5 days
The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is June (10.3 days).
Average UV index in September
Downs, IL
- Average UV index in September: 5
The months with the highest UV index are June and 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
Downs, IL
- Average cloud cover in September: 31
The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is September (Cloud cover 31).
Average visibility in September
Downs, 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).
Downs, Illinois, USA
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