September weather forecastIrwin, IL
September
Weather in September
September, the first month of the autumn in Irwin, is still a warm month, with an average temperature ranging between min 57.2°F (14°C) and max 75°F (23.9°C).Temperature
In September, the average high-temperature registers at a still moderately hot 75°F (23.9°C), nearly identical to August's 79.7°F (26.5°C). In September, Irwin reports a consistent average low-temperature of 57.2°F (14°C) during the nights.Humidity
The average relative humidity in September is 77%.Rainfall
In Irwin, in September, it is raining for 12.2 days, with typically 1.57" (40mm) of accumulated precipitation. In Irwin, during the entire year, the rain falls for 142.1 days and collects up to 22.56" (573mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
The average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:19 am and sunset at 7:24 pm. On the last day of September, sunrise is at 6:48 am and sunset at 6:35 pm CDT.
Sunshine
In September, the average sunshine is 8.7h.UV index
In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for the average person.Note: The daily high UV index of 5 during September translates into the following recommendations:
Undertake precautions - It is suggested to shield oneself from sunburn. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. Employ a hat with a wide brim for robust protection, cutting UV exposure by half.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Irwin, IL
- Average high temperature in September: 75°F
The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (30°F).
- Average low temperature in September: 57.2°F
The month with the highest average low temperature is July (64.2°F).
The coldest month (with the lowest average low temperature) is January (18.3°F).
Average pressure in September
Irwin, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Irwin, IL
- Average wind speed in September: 7.2mph
The windiest months (with the highest average wind speed) are January and April (10.2mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).
Average humidity in September
Irwin, IL
- Average humidity in September: 77%
The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Irwin, IL
- Average rainfall in September: 1.57"
The wettest month (with the highest rainfall) is May (3.27").
The driest month (with the least rainfall) is February (1.06").
Average rainfall days in September
Irwin, IL
- Average rainfall days in September: 12.2 days
The month with the highest number of rainy days is May (17.8 days).
The month with the least rainy days is February (5 days).
Average snowfall in September
Irwin, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.17").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Irwin, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.7 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
Irwin, IL
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 8h and 42min
The months with the most sunshine are June and July (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in September
Irwin, IL
- Average sunshine days in September: 14.7 days
The month with the most sunshine days is November (18.7 days).
The month with the least sunshine days is July (9.3 days).
Average UV index in September
Irwin, 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 and December (UV index 1).
Average cloud cover in September
Irwin, IL
- Average cloud cover in September: 34
The month with the most cloud cover is January (Cloud cover 60).
The months with the least cloud cover are August and September (Cloud cover 34).
Average visibility in September
Irwin, 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).
