September weather forecastForest Lake, IL
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Forest Lake, Illinois, with an average temperature varying between 72.9°F (22.7°C) and 57.2°F (14°C).Temperature
The transition into September is accompanied by a slight temperature decrease, with the average high-temperature shifting from a warm 79.3°F (26.3°C) in August to an agreeable 72.9°F (22.7°C). In September, Forest Lake encounters an average low-temperature of 57.2°F (14°C) during the night.Humidity
In Forest Lake, the average relative humidity in September is 77%.Rainfall
In Forest Lake, in September, during 13.4 rainfall days, 2.2" (56mm) of precipitation is typically accumulated. Throughout the year, there are 163.1 rainfall days, and 32.24" (819mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.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 6:48 am and sunset at 6:34 pm CDT.
Sunshine
In Forest Lake, the average sunshine in September is 9h.UV index
The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for average individuals.Note: In September, the maximum UV index of 4 transforms into these recommendations:
Act with care - The suggestion to avoid sunburn is emphasized. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Forest Lake, 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
Forest Lake, 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
Forest Lake, 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
Forest Lake, 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
Forest Lake, 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
Forest Lake, 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
Forest Lake, 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
Forest Lake, 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
Forest Lake, 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: 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
Forest Lake, 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
Forest Lake, 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
Forest Lake, 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
Forest Lake, 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).
