September weather forecastCrystal Lawns, IL
September
Weather in September
September, the first month of the autumn in Crystal Lawns, is still a warm month, with an average temperature varying between 56.7°F (13.7°C) and 74.7°F (23.7°C).Temperature
September brings a minor shift in the average high-temperature, adjusting from 80.1°F (26.7°C) in August to a still moderately hot 74.7°F (23.7°C). An average low-temperature of 56.7°F (13.7°C) marks the nights throughout September.Humidity
In September, the average relative humidity is 78%.Rainfall
In Crystal Lawns, in September, it is raining for 12.5 days, with typically 2.48" (63mm) of accumulated precipitation. In Crystal Lawns, during the entire year, the rain falls for 153.6 days and collects up to 32.72" (831mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
In September, the average length of the day is 12h and 28min.On the first day of the month, sunrise is at 6:19 am and sunset at 7:25 pm. On the last day of September, sunrise is at 6:49 am and sunset at 6:35 pm CDT.
Sunshine
In Crystal Lawns, the average sunshine in September is 8.5h.UV index
In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for the average person.Note: A maximum high daily UV index of 4 during September translates into the following directions:
Take necessary precautions - Protection from skin and eye injury is mandatory. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Crystal Lawns, IL
- Average high temperature in September: 74.7°F
The warmest month (with the highest average high temperature) is July (81.3°F).
The month with the lowest average high temperature is January (29.3°F).
- Average low temperature in September: 56.7°F
The month with the highest average low temperature is July (64.8°F).
The coldest month (with the lowest average low temperature) is January (17.4°F).
Average pressure in September
Crystal Lawns, 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
Crystal Lawns, IL
- Average wind speed in September: 6.9mph
The windiest month (with the highest average wind speed) is April (9.7mph).
The calmest month (with the lowest average wind speed) is August (5.9mph).
Average humidity in September
Crystal Lawns, IL
- Average humidity in September: 78%
The month with the highest relative humidity is February (83%).
The month with the lowest relative humidity is October (73%).
Average rainfall in September
Crystal Lawns, IL
- Average rainfall in September: 2.48"
The wettest month (with the highest rainfall) is May (4.41").
The driest month (with the least rainfall) is February (1.61").
Average rainfall days in September
Crystal Lawns, IL
- Average rainfall days in September: 12.5 days
The month with the highest number of rainy days is July (17.9 days).
The month with the least rainy days is February (5.7 days).
Average snowfall in September
Crystal Lawns, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.33").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Crystal Lawns, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.9 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
Crystal Lawns, 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 12min).
- Average sunshine in September: 8h and 30min
The month with the most sunshine is August (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in September
Crystal Lawns, IL
- Average sunshine days in September: 15 days
The month with the most sunshine days is November (18.1 days).
The month with the least sunshine days is June (10.4 days).
Average UV index in September
Crystal Lawns, IL
- Average UV index in September: 4
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
Crystal Lawns, 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
Crystal Lawns, IL
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, February, July and August (5mi).
