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
The move into September indicates a slight reduction in the average high-temperature, down from August's warm 79.3°F (26.3°C) to a pleasant 72.9°F (22.7°C). An average nighttime temperature of 57.2°F (14°C) is recorded during September.Humidity
The average relative humidity in September is 77%.Rainfall
In Deer Park, in September, it is raining for 13.4 days, with typically 2.2" (56mm) of accumulated precipitation. In Deer Park, during the entire year, the rain falls for 163.1 days and collects up to 32.24" (819mm) of precipitation.Snowfall
In Deer Park, snow does not fall in June through September.Daylight
The average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:18 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 Deer Park, the average sunshine in September is 9h.UV index
The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for average individuals.Note: The maximum UV index of 4 during September translates into these guidelines:
Exercise prudence. Persons with fair skin could be burned in under 30 minutes. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the average humidity in September?
How many days 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?
What time are sunrise and sunset in September?
How long on average sun shines in September in Deer Park?
What is the UV index intensity in September?
Average temperature in September
Deer Park, IL
- Average high temperature in September: 72.9°F
The warmest month (with the highest average high temperature) is July (80.6°F).
The month with the lowest average high temperature is January (27.7°F).
- Average low temperature in September: 57.2°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 (16.3°F).
Average pressure in September
Deer Park, 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
Deer Park, IL
- Average wind speed in September: 7.3mph
The windiest month (with the highest average wind speed) is January (10.1mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).
Average humidity in September
Deer Park, IL
- Average humidity in September: 77%
The months with the highest relative humidity are January and February (83%).
The month with the lowest relative humidity is October (74%).
Average rainfall in September
Deer Park, IL
- Average rainfall in September: 2.2"
The wettest month (with the highest rainfall) is June (4.13").
The driest month (with the least rainfall) is November (1.61").
Average rainfall days in September
Deer Park, IL
- Average rainfall days in September: 13.4 days
The month with the highest number of rainy days is May (20 days).
The month with the least rainy days is February (5.7 days).
Average snowfall in September
Deer Park, IL
- Average snowfall in September: 0"
The month with the highest snowfall is February (6.22").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Deer Park, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (15.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Deer Park, 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: 9h and 0min
The months with the most sunshine are July and August (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in September
Deer Park, IL
- Average sunshine days in September: 13.4 days
The month with the most sunshine days is November (15.5 days).
The month with the least sunshine days is June (8.4 days).
Average UV index in September
Deer Park, IL
- Average UV index in September: 4
The months with the highest UV index are July and August (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Deer Park, IL
- Average cloud cover in September: 31
The month with the most cloud cover is January (Cloud cover 61).
The months with the least cloud cover are July, August and September (Cloud cover 31).
Average visibility in September
Deer Park, 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).
Deer Park, Illinois, USA
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