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 sea temperature 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 marks a gentle change in average high-temperature, declining from August's warm 77.5°F (25.3°C) to a pleasant 71.2°F (21.8°C). September generally records an average low-temperature of 60.1°F (15.6°C).Humidity
In September, the average relative humidity is 75%.Rainfall
In Lake Bluff, in September, during 13.6 rainfall days, 2.6" (66mm) of precipitation is typically accumulated. In Lake Bluff, during the entire year, the rain falls for 154.1 days and collects up to 30.24" (768mm) of precipitation.Snowfall
May through September are months without snowfall.Ocean temperature
In September, the average ocean temperature is 68.5°F (20.3°C).Note: For most, swimming in 68.5°F (20.3°C) is not an enjoyable activity. Furthermore, controlling your breathing becomes progressively more difficult as the water temperature decreases from 69.8°F (21°C) to 59°F (15°C).
Daylight
In September, the average length of the day is 12h and 28min.On the first day of September in Lake Bluff, sunrise is at 6:17 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
The average sunshine in September in Lake Bluff is 9.2h.UV index
The average daily maximum UV index in September in Lake Bluff is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV radiation for the ordinary person.Note: An average maximum UV index of 4 in September leads to these recommendations:
Undertake protective steps - Preventing sun damage is advised. The mid-day Sun emits the most powerful UV radiation, so seek shade and minimize exposure. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures 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 ocean temperature in September?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Lake Bluff have in September?
What is the UV index reading in September?
Average temperature in September
Lake Bluff, 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
Lake Bluff, 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
Lake Bluff, 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
Lake Bluff, 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
Lake Bluff, 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
Lake Bluff, 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
Lake Bluff, 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
Lake Bluff, 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 sea temperature in September
Lake Bluff, IL
- Average sea temperature in September: 68.5°F
The best month for swimming (with the highest average sea temperature) is August (73.3°F).
The coldest month (with the lowest average sea temperature) is February (37.1°F).
Average daylight in September /
Average sunshine in September
Lake Bluff, 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 6min).
- 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
Lake Bluff, 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
Lake Bluff, 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
Lake Bluff, 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
Lake Bluff, 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).
Lake Bluff, Illinois, USA
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