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
The arrival of September denotes a barely perceptible change in the average high-temperatures to a still moderately hot 76.6°F (24.8°C) from August's 81°F (27.2°C). During the nights in September, Monticello observes an average low-temperature of 58.3°F (14.6°C).Humidity
The average relative humidity in September is 76%.Rainfall
In Monticello, in September, it is raining for 10.2 days, with typically 0.98" (25mm) of accumulated precipitation. Throughout the year, in Monticello, there are 127.9 rainfall days, and 16.61" (422mm) of precipitation is accumulated.Snowfall
In Monticello, snow does not fall in May through October.Daylight
In September, the average length of the day is 12h and 26min.On the first day of the month, sunrise is at 6:22 am and sunset at 7:25 pm. On the last day of September, in Monticello, sunrise is at 6:50 am and sunset at 6:37 pm CDT.
Sunshine
The average sunshine in September in Monticello is 8.9h.UV index
The average daily maximum UV index in September in Monticello is 5. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for the ordinary person.Note: In September, an average UV index of 5 transforms into the following instructions:
Exercise caution. The susceptibility of light skin individuals to burns is less than 30 minutes. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days.
Frequently asked questions
What are the temperatures in Monticello in September?
What is the average humidity in September in Monticello?
How much does it rain in Monticello in September?
When it does not snow in Monticello?
How many hours of daylight does Monticello have in September?
What time are sunrise and sunset in September in Monticello?
How many hours of sunshine does Monticello have in September?
How high is the UV index in September in Monticello?
Average temperature in September
Monticello, IL
- Average high temperature in September: 76.6°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 (32.4°F).
- Average low temperature in September: 58.3°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 (20.3°F).
Average pressure in September
Monticello, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Monticello, IL
- Average wind speed in September: 7.4mph
The windiest month (with the highest average wind speed) is January (10.9mph).
The calmest month (with the lowest average wind speed) is August (6.4mph).
Average humidity in September
Monticello, IL
- Average humidity in September: 76%
The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (70%).
Average rainfall in September
Monticello, IL
- Average rainfall in September: 0.98"
The wettest month (with the highest rainfall) is May (2.09").
The driest month (with the least rainfall) is December (0.91").
Average rainfall days in September
Monticello, IL
- Average rainfall days in September: 10.2 days
The month with the highest number of rainy days is May (16.3 days).
The month with the least rainy days is February (5.2 days).
Average snowfall in September
Monticello, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.05").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Monticello, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (8.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Monticello, IL
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is June (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in September
Monticello, IL
- Average sunshine days in September: 17.6 days
The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is May (12.3 days).
Average UV index in September
Monticello, IL
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Monticello, IL
- Average cloud cover in September: 32
The month with the most cloud cover is January (Cloud cover 57).
The months with the least cloud cover are June, August and September (Cloud cover 32).
Average visibility in September
Monticello, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
Monticello, Illinois, USA
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