September weather forecastLyndon, IL
September
Weather in September
September, the first month of the autumn in Lyndon, is also a moderately hot month, with temperature in the range of an average low of 55.8°F (13.2°C) and an average high of 74.7°F (23.7°C).Temperature
Lyndon experiences an average high-temperature of a still warm 74.7°F (23.7°C) in September, marking an insignificant shift from 79.9°F (26.6°C) in August. The average temperature during September nights is registered at a mild 55.8°F (13.2°C).Humidity
In September, the average relative humidity is 77%.Rainfall
In September, the rain falls for 12.5 days. Throughout September, 2.2" (56mm) of precipitation is accumulated. Throughout the year, there are 151.5 rainfall days, and 30.24" (768mm) of precipitation is accumulated.Snowfall
In Lyndon, snow does not fall in May through September.Daylight
In Lyndon, the average length of the day in September is 12h and 28min.On the first day of September in Lyndon, sunrise is at 6:26 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:56 am and sunset at 6:42 pm CDT.
Sunshine
In September, the average sunshine is 9.2h.UV index
In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for the ordinary person.Note: In September, a daily UV index of 4 turns into the following recommendations:
Take necessary precautions - Defending against sun damage is advocated. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Lyndon, IL
- Average high temperature in September: 74.7°F
The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is January (27.7°F).
- Average low temperature in September: 55.8°F
The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (15.1°F).
Average pressure in September
Lyndon, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Lyndon, IL
- Average wind speed in September: 7.6mph
The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity in September
Lyndon, IL
- Average humidity in September: 77%
The months with the highest relative humidity are January and July (85%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Lyndon, IL
- Average rainfall in September: 2.2"
The wettest month (with the highest rainfall) is May (4.53").
The driest month (with the least rainfall) is January (1.42").
Average rainfall days in September
Lyndon, IL
- Average rainfall days in September: 12.5 days
The month with the highest number of rainy days is May (18.8 days).
The month with the least rainy days is January (5.2 days).
Average snowfall in September
Lyndon, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.49").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Lyndon, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (10.5 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
Lyndon, 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 12min
The month with the most sunshine is July (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in September
Lyndon, IL
- Average sunshine days in September: 15.7 days
The month with the most sunshine days is November (17.8 days).
The month with the least sunshine days is June (9.1 days).
Average UV index in September
Lyndon, 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
Lyndon, IL
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 59).
The month with the least cloud cover is September (Cloud cover 30).
Average visibility in September
Lyndon, IL
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, July and August (5mi).
