September weather forecastNorthlake, IL
September
Weather in September
September, the first month of the autumn in Northlake, is still a warm month, with an average temperature ranging between min 58.6°F (14.8°C) and max 73.4°F (23°C).Temperature
September is characterized by a mild reduction in the average high-temperature, from 80.2°F (26.8°C) in August to a still warm 73.4°F (23°C). Northlake observes an average nighttime temperature of 58.6°F (14.8°C) during September.Humidity
In Northlake, Illinois, the average relative humidity in September is 74%.Rainfall
In Northlake, Illinois, in September, it is raining for 13.5 days, with typically 1.89" (48mm) of accumulated precipitation. In Northlake, Illinois, during the entire year, the rain falls for 149.4 days and collects up to 25.08" (637mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 28min.On the first day of September, 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 Northlake, the average sunshine in September 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 health hazard from unprotected exposure to Sun's UV rays for average individuals.Note: In September, the average maximum UV index of 4 translates into the following recommendations:
Take measures. Individuals with light skin might experience burns in under 30 minutes. Minimize direct exposure to the Sun during midday when its radiation is at its peak. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Northlake, IL
- Average high temperature in September: 73.4°F
The warmest month (with the highest average high temperature) is July (81.9°F).
The month with the lowest average high temperature is January (28.8°F).
- Average low temperature in September: 58.6°F
The month with the highest average low temperature is July (66.6°F).
The coldest month (with the lowest average low temperature) is January (18°F).
Average pressure in September
Northlake, 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
Northlake, IL
- Average wind speed in September: 7.5mph
The windiest month (with the highest average wind speed) is January (10.2mph).
The calmest month (with the lowest average wind speed) is August (6.3mph).
Average humidity in September
Northlake, 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
Northlake, IL
- Average rainfall in September: 1.89"
The wettest month (with the highest rainfall) is May (3.11").
The driest month (with the least rainfall) is December (1.14").
Average rainfall days in September
Northlake, IL
- Average rainfall days in September: 13.5 days
The months with the highest number of rainy days are May and July (17.3 days).
The month with the least rainy days is February (5.1 days).
Average snowfall in September
Northlake, IL
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.86").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Northlake, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (12.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Northlake, 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 12min).
- Average sunshine in September: 8h and 48min
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
Northlake, IL
- Average sunshine days in September: 13 days
The month with the most sunshine days is November (16.8 days).
The month with the least sunshine days is July (9.5 days).
Average UV index in September
Northlake, IL
- Average UV index in September: 4
The months with the highest UV index are June, 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
Northlake, 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 30).
Average visibility in September
Northlake, 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).





