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 start of September involves a subtle temperature drop, shifting from a moderately hot 77.5°F (25.3°C) in August to a pleasant 71.2°F (21.8°C). Deerfield records an average temperature drop to a mild 60.1°F (15.6°C) in September.Humidity
In Deerfield, Illinois, the average relative humidity in September is 75%.Rainfall
In Deerfield, Illinois, during September, the rain falls for 13.6 days and regularly aggregates up to 2.6" (66mm) of precipitation. Throughout the year, in Deerfield, Illinois, there are 154.1 rainfall days, and 30.24" (768mm) of precipitation is accumulated.Snowfall
In Deerfield, snow does not fall in May through September.Daylight
In September, the average length of the day in Deerfield is 12h and 28min.On the first day of the month, sunrise is at 6:17 am and sunset at 7:24 pm. On the last day of September, sunrise is at 6:48 am and sunset at 6:34 pm CDT.
Sunshine
The average sunshine in September in Deerfield is 9.2h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for the ordinary person.Note: The daily maximum UV index of 4 in September interprets into the following advice:
Guard yourself - Avoiding sunburn is suggested. Minimize direct exposure to the Sun during midday when its radiation is at its peak. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim.
Frequently asked questions
What is the usual temperature for Deerfield in September?
What is the average humidity in September in Deerfield?
How many days does it rain in September in Deerfield?
When it does not snow in Deerfield?
Does it snow in Deerfield in September?
What is the average length of the day in September in Deerfield?
When are sunrise and sunset in September in Deerfield?
How long on average sun shines in September in Deerfield?
What is the UV index intensity in September in Deerfield?
Average temperature in September
Deerfield, IL
- Average high temperature in September: 71.2°F
The warmest month (with the highest average high temperature) is July (77.7°F).
The month with the lowest average high temperature is January (28.6°F).
- Average low temperature in September: 60.1°F
The months with the highest average low temperature are July and August (66.7°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure in September
Deerfield, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Deerfield, IL
- Average wind speed in September: 8.9mph
The windiest month (with the highest average wind speed) is January (11.9mph).
The calmest month (with the lowest average wind speed) is August (7.4mph).
Average humidity in September
Deerfield, IL
- Average humidity in September: 75%
The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is October (73%).
Average rainfall in September
Deerfield, IL
- Average rainfall in September: 2.6"
The wettest months (with the highest rainfall) are May and June (3.82").
The driest month (with the least rainfall) is December (1.3").
Average rainfall days in September
Deerfield, IL
- Average rainfall days in September: 13.6 days
The month with the highest number of rainy days is May (17.7 days).
The month with the least rainy days is February (5.9 days).
Average snowfall in September
Deerfield, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.13").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Deerfield, 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
Deerfield, 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 1min
The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in September
Deerfield, IL
- Average sunshine days in September: 13.3 days
The month with the most sunshine days is December (15.3 days).
The month with the least sunshine days is April (10.8 days).
Average UV index in September
Deerfield, 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
Deerfield, IL
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 61).
The months with the least cloud cover are July and August (Cloud cover 27).
Average visibility in September
Deerfield, 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).
Deerfield, Illinois, USA
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