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
September is marked by a subtle drop in average high-temperatures, transitioning from a warm 78.1°F (25.6°C) in August to a pleasant 72.7°F (22.6°C). Throughout the month of September, Byron observes an average nighttime temperature of 54.3°F (12.4°C).Humidity
The average relative humidity in September is 80%.Rainfall
In Byron, in September, during 7.7 rainfall days, 0.63" (16mm) of precipitation is typically accumulated. Throughout the year, there are 100.6 rainfall days, and 7.99" (203mm) of precipitation is accumulated.Snowfall
In Byron, Illinois, snow does not fall in May through September.Daylight
In September, the average length of the day is 12h and 28min.On the first day of September, sunrise is at 6:23 am and sunset at 7:30 pm. On the last day of the month, sunrise is at 6:53 am and sunset at 6:39 pm CDT.
Sunshine
In Byron, the average sunshine in September is 8.7h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for average individuals.Note: In September, a regular UV index of 4 translates into these guidelines:
Undertake precautions - Guarding against sun damage is counselled. The solar radiation around mid-day is intense; avoid the Sun and stay safe. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature 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 average length of the day in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Byron have in September?
What is the UV index reading in September in Byron?
Average temperature in September
Byron, IL
- Average high temperature in September: 72.7°F
The warmest month (with the highest average high temperature) is July (79.9°F).
The month with the lowest average high temperature is January (26.2°F).
- Average low temperature in September: 54.3°F
The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (14°F).
Average pressure in September
Byron, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Byron, IL
- Average wind speed in September: 7.4mph
The windiest month (with the highest average wind speed) is April (10.2mph).
The calmest month (with the lowest average wind speed) is August (6.3mph).
Average humidity in September
Byron, IL
- Average humidity in September: 80%
The month with the highest relative humidity is January (86%).
The months with the lowest relative humidity are April and October (75%).
Average rainfall in September
Byron, IL
- Average rainfall in September: 0.63"
The wettest month (with the highest rainfall) is May (1.18").
The driest months (with the least rainfall) are January and February (0.35").
Average rainfall days in September
Byron, IL
- Average rainfall days in September: 7.7 days
The month with the highest number of rainy days is May (13.8 days).
The month with the least rainy days is January (3.2 days).
Average snowfall in September
Byron, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.42").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Byron, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (8.1 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
Byron, 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: 8h and 4min
The month with the most sunshine is July (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in September
Byron, IL
- Average sunshine days in September: 20 days
The month with the most sunshine days is December (22.6 days).
The month with the least sunshine days is June (12.8 days).
Average UV index in September
Byron, IL
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Byron, IL
- Average cloud cover in September: 33
The month with the most cloud cover is January (Cloud cover 62).
The month with the least cloud cover is September (Cloud cover 33).
Average visibility in September
Byron, 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).
Byron, Illinois, USA
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