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
September brings a minor shift in the average high-temperature in Mount Prospect, adjusting from a warm 79.7°F (26.5°C) in August to a pleasant 73.2°F (22.9°C). Throughout September, the average low-temperature records at a moderate 58.8°F (14.9°C).Humidity
In Mount Prospect, Illinois, the average relative humidity in September is 74%.Rainfall
In September, the rain falls for 13.2 days. Throughout September, 2.24" (57mm) of precipitation is accumulated. Throughout the year, in Mount Prospect, there are 153.3 rainfall days, and 30.12" (765mm) of precipitation is accumulated.Snowfall
In Mount Prospect, snow does not fall in June through September.Daylight
In Mount Prospect, the average length of the day in September is 12h and 28min.On the first day of September in Mount Prospect, sunrise is at 6:18 am and sunset at 7:24 pm. On the last day of the month, sunrise is at 6:48 am and sunset at 6:34 pm CDT.
Sunshine
In September, the average sunshine is 8.8h.UV index
In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for the ordinary person.Note: An average UV index of 4 in September transforms into this advice:
Stay alert. Light-skinned people could suffer burns in less than 30 minutes. The mid-day Sun emits the most powerful UV radiation, so seek shade and minimize exposure. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Mount Prospect in September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
Does it snow in September?
What is the average length of the day in September?
When are sunrise and sunset in September?
How many hours of sunshine does Mount Prospect have in September?
What is the UV index intensity in September?
Average temperature in September
Mount Prospect, IL
- Average high temperature in September: 73.2°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 (28.2°F).
- Average low temperature in September: 58.8°F
The month with the highest average low temperature is July (66.4°F).
The coldest month (with the lowest average low temperature) is January (18°F).
Average pressure in September
Mount Prospect, 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
Mount Prospect, IL
- Average wind speed in September: 7.7mph
The windiest month (with the highest average wind speed) is January (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity in September
Mount Prospect, IL
- Average humidity in September: 74%
The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Mount Prospect, IL
- Average rainfall in September: 2.24"
The wettest month (with the highest rainfall) is May (3.9").
The driest month (with the least rainfall) is December (1.46").
Average rainfall days in September
Mount Prospect, IL
- Average rainfall days in September: 13.2 days
The month with the highest number of rainy days is May (18 days).
The month with the least rainy days is February (5.6 days).
Average snowfall in September
Mount Prospect, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.96").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Mount Prospect, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Mount Prospect, IL
- Average daylight in September: 12h and 3min
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 12min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is July (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in September
Mount Prospect, IL
- Average sunshine days in September: 14.1 days
The month with the most sunshine days is November (16.3 days).
The month with the least sunshine days is June (10.7 days).
Average UV index in September
Mount Prospect, IL
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Mount Prospect, IL
- Average cloud cover in September: 31
The month with the most cloud cover is January (Cloud cover 61).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in September
Mount Prospect, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Mount Prospect, Illinois, USA
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