September weather forecastMcHenry, IL
September
Weather in September
September, the first month of the autumn in McHenry, is also an agreeable month, with an average temperature varying between 55°F (12.8°C) and 72.3°F (22.4°C).Temperature
A moderate decline in average high-temperatures is noted in September, moving from a warm 78.1°F (25.6°C) in August to an agreeable 72.3°F (22.4°C). McHenry's average low-temperature in the month of September is recorded at a cool 55°F (12.8°C).Humidity
In McHenry, the average relative humidity in September is 80%.Rainfall
In McHenry, during September, the rain falls for 13.5 days and regularly aggregates up to 2.09" (53mm) of precipitation. Throughout the year, there are 152.4 rainfall days, and 28.07" (713mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall in McHenry.Daylight
In McHenry, the average length of the day in September is 12h and 28min.On the first day of September in McHenry, sunrise is at 6:19 am and sunset at 7:26 pm. On the last day of the month, sunrise is at 6:49 am and sunset at 6:35 pm CDT.
Sunshine
In September, the average sunshine is 8.9h.UV index
The average daily maximum UV index in September in McHenry is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for ordinary individuals.Note: The UV index of 4 in September translates into these instructions:
Stay alert. Light-skinned people could suffer burns in less than 30 minutes. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. Sun protection is enhanced with clothing that boasts a tight weave yet offers a loose fit.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
McHenry, IL
- Average high temperature in September: 72.3°F
The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is January (26.6°F).
- Average low temperature in September: 55°F
The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (14.9°F).
Average pressure in September
McHenry, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
McHenry, IL
- Average wind speed in September: 7.3mph
The windiest month (with the highest average wind speed) is January (10mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).
Average humidity in September
McHenry, IL
- Average humidity in September: 80%
The months with the highest relative humidity are January and February (85%).
The month with the lowest relative humidity is October (76%).
Average rainfall in September
McHenry, IL
- Average rainfall in September: 2.09"
The wettest month (with the highest rainfall) is June (3.58").
The driest month (with the least rainfall) is December (1.34").
Average rainfall days in September
McHenry, IL
- Average rainfall days in September: 13.5 days
The month with the highest number of rainy days is July (18.3 days).
The month with the least rainy days is February (4.9 days).
Average snowfall in September
McHenry, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (5.16").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
McHenry, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (13.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
McHenry, IL
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 8h and 54min
The months with the most sunshine are July and August (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in September
McHenry, IL
- Average sunshine days in September: 14.3 days
The month with the most sunshine days is November (16 days).
The month with the least sunshine days is June (10.2 days).
Average UV index in September
McHenry, IL
- Average UV index in September: 4
The month with the highest UV index is August (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
McHenry, IL
- Average cloud cover in September: 31
The month with the most cloud cover is January (Cloud cover 62).
The months with the least cloud cover are August and September (Cloud cover 31).
Average visibility in September
McHenry, IL
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and February (5mi).
