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Contents
- Weather in January
- Weather in February
- Weather in March
- Weather in April
- Weather in May
- Weather in June
- Weather in July
- Weather in August
- Weather in September
- Weather in October
- Weather in November
- Weather in December
- Frequently asked questions
- Average temperature
- Average pressure
- Average wind speed
- Average humidity
- Average rainfall
- Average rainfall days
- Average snowfall
- Average snowfall days
- Average daylight
- Average sunshine
- Average sunshine days
- Average UV index
- Average cloud cover
- Average visibility
Weather in January
January, like December, is a freezing cold winter month in Illinois City, Illinois, with an average temperature ranging between min 16.2°F (-8.8°C) and max 28.2°F (-2.1°C). January stands out as Illinois City's coldest month, with an average high-temperature of 28.2°F (-2.1°C) and a low-temperature of 16.2°F (-8.8°C). Weather in January »
Weather in February
February, the last month of the winter in Illinois City, is a wintry month, with an average temperature varying between 20.1°F (-6.6°C) and 33.1°F (0.6°C). On the advent of February, Illinois City's average high-temperature exhibits a minor adjustment to a wintry 33.1°F (0.6°C) from January's 28.2°F (-2.1°C). Weather in February »
Weather in March
March, the first month of the spring in Illinois City, is a chilly month, with an average temperature fluctuating between 46.9°F (8.3°C) and 32.2°F (0.1°C). The start of March brings a shift in the average high-temperature, increasing from February's icy 33.1°F (0.6°C) to a frosty 46.9°F (8.3°C). Weather in March »
Weather in April
April in Illinois City, Illinois, is a refreshing spring month, with temperature in the range of an average low of 42.4°F (5.8°C) and an average high of 59.2°F (15.1°C). With the transition into April, Illinois City experiences an increase in average high-temperatures, moving up from a chilly 46.9°F (8.3°C) in March to a mild 59.2°F (15.1°C). Weather in April »
Weather in May
The last month of the spring, May, is a pleasant month in Illinois City, Illinois, with an average temperature ranging between min 53.6°F (12°C) and max 70.3°F (21.3°C). The shift into May is characterized by a rise in the average high-temperature, transitioning from April's refreshing 59.2°F (15.1°C) to an agreeable 70.3°F (21.3°C). Weather in May »
Weather in June
June, the first month of the summer in Illinois City, is a moderately hot month, with an average temperature varying between 79°F (26.1°C) and 62.4°F (16.9°C). With the onset of June, Illinois City experiences a subtle temperature shift, with the average high-temperature moving from a pleasant 70.3°F (21.3°C) in May to a warm 79°F (26.1°C). Weather in June »
Weather in July
July, like June, in Illinois City, Illinois, is another warm summer month, with an average temperature fluctuating between 81.7°F (27.6°C) and 65.1°F (18.4°C). July, on average, is the warmest month, registering a high temperature of 81.7°F (27.6°C) and a low of 65.1°F (18.4°C). For July, the heat index is appraised at a tropical 89.6°F (32°C). Weather in July »
Weather in August
The last month of the summer, August, is also a moderately hot month in Illinois City, Illinois, with temperature in the range of an average high of 80.8°F (27.1°C) and an average low of 63.1°F (17.3°C). August welcomes an average high-temperature of a still warm 80.8°F (27.1°C), not much different from the preceding month. Weather in August »
Weather in September
The first month of the autumn, September, is still a warm month in Illinois City, Illinois, with an average temperature fluctuating between 75.4°F (24.1°C) and 56.3°F (13.5°C). As August shifts into September, a minor alteration in temperatures is observed, with average highs reducing from 80.8°F (27.1°C) to a still moderately hot 75.4°F (24.1°C). Weather in September »
Weather in October
October, the same as September, is another refreshing autumn month in Illinois City, Illinois, with an average temperature varying between 45.1°F (7.3°C) and 61.5°F (16.4°C). With the beginning of October, the average high-temperature shows a decrease, transitioning from a warm 75.4°F (24.1°C) in September to a refreshing 61.5°F (16.4°C). Weather in October »
Weather in November
The last month of the autumn, November, is also a frosty month in Illinois City, Illinois, with an average temperature ranging between min 33.3°F (0.7°C) and max 47.1°F (8.4°C). Illinois City's average high-temperature decreases in November, falling from an enjoyable 61.5°F (16.4°C) in October to a frosty 47.1°F (8.4°C). Weather in November »
Weather in December
December, the first month of the winter in Illinois City, is still a cold month, with an average temperature ranging between min 24.1°F (-4.4°C) and max 34.5°F (1.4°C). During the transition into December, Illinois City observes a decrease in the average high-temperature, falling from a frosty 47.1°F (8.4°C) in November to a wintry 34.5°F (1.4°C). Weather in December »
Updated: Aug 7, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the coldest time of year?
Illinois City's coldest weather arrives in January, when temperatures average a high of 28.2°F (-2.1°C) and a low of 16.2°F (-8.8°C).
What are the most humid months?
January and July, with an average relative humidity of 83%, are most humid months.
How much does it rain?
Throughout the year, there are 128 rainfall days, and 19.29" (490mm) of precipitation is accumulated.
When does it snow?
January through April, October through December are months with snowfall.
How many days does it snow?
In Illinois City, during the entire year, snow falls for 35.4 days and aggregates up to 8.35" (212mm) of snow.
What is the month with the least sunshine?
January has the least sunshine of the year, with an average of 4h of sunshine.
What is the month with the lowest UV index?
The month with the lowest UV index is January, with an average maximum UV index of 1.
When does it snow the most?
February is the month with the most snowfall in Illinois City. Snow falls for 8.8 days and accumulates 2.52" (64mm) of snow.
When is Daylight Saving Time (DST)?
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from CST to CDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from CDT to CST.
What is the wettest month?
The month with the most rainfall is May, when the rain falls for 16.5 days and typically aggregates up to 3.31" (84mm) of precipitation.
When it does not snow?
May through September are months without snowfall.
When are the longest days?
With an average of 15h and 6min of daylight, June has the longest days of the year.
What is the month with the highest UV index?
June and July, with an average maximum UV index of 6, are months with the highest UV index in Illinois City.
What are the warmest months?
Illinois City's warmest temperatures are experienced in July, with average high temperatures of 81.7°F (27.6°C) and lows of 65.1°F (18.4°C).
What month has the most sunshine?
The month with the most sunshine is July, with an average of 10.3h of sunshine.
What is the least humid month in Illinois City?
The least humid month is October, with an average relative humidity of 71%.
What is the driest month?
December is the month with the least rainfall. Rain falls for 6.6 days and accumulates 0.75" (19mm) of precipitation.
What is the month with the shortest days?
The month with the shortest days is December, with an average of 9h and 12min of daylight.
Average temperature
Illinois City, IL
The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (28.2°F).
The month with the highest average low temperature is July (65.1°F).
The coldest month (with the lowest average low temperature) is January (16.2°F).
Average pressure
Illinois City, IL
- Average pressure in January:
30.14"Hg - Average pressure in February:
30.12"Hg - Average pressure in March:
30.08"Hg - Average pressure in April:
29.93"Hg - Average pressure in May:
29.94"Hg - Average pressure in June:
29.9"Hg
- Average pressure in July:
29.96"Hg - Average pressure in August:
29.97"Hg - Average pressure in September:
30.02"Hg - Average pressure in October:
30.01"Hg - Average pressure in November:
30.09"Hg - Average pressure in December:
30.11"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed
Illinois City, IL
- Average wind speed in January:
10.4mph - Average wind speed in February:
10.4mph - Average wind speed in March:
10.3mph - Average wind speed in April:
10.6mph - Average wind speed in May:
9mph - Average wind speed in June:
7.8mph
- Average wind speed in July:
6.8mph - Average wind speed in August:
6.7mph - Average wind speed in September:
7.8mph - Average wind speed in October:
9.6mph - Average wind speed in November:
10.3mph - Average wind speed in December:
9.8mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.7mph).
Average humidity
Illinois City, IL
The months with the highest relative humidity are January and July (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall
Illinois City, IL
- Average rainfall in January:
0.79" - Average rainfall in February:
0.79" - Average rainfall in March:
1.1" - Average rainfall in April:
2.01" - Average rainfall in May:
3.31" - Average rainfall in June:
2.8"
The wettest month (with the highest rainfall) is May (3.31").
The driest month (with the least rainfall) is December (0.75").
Average rainfall days
Illinois City, IL
- Average rainfall days in January:
4.2 days - Average rainfall days in February:
4.3 days - Average rainfall days in March:
9.8 days - Average rainfall days in April:
14.3 days - Average rainfall days in May:
16.5 days - Average rainfall days in June:
17 days
- Average rainfall days in July:
15 days - Average rainfall days in August:
12.3 days - Average rainfall days in September:
9.5 days - Average rainfall days in October:
11.1 days - Average rainfall days in November:
7.4 days - Average rainfall days in December:
6.6 days
The month with the highest number of rainy days is June (17 days).
The month with the least rainy days is January (4.2 days).
Average snowfall
Illinois City, IL
The month with the highest snowfall is February (2.52").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days
Illinois City, IL
- Average snowfall days in January:
10.3 days - Average snowfall days in February:
8.8 days - Average snowfall days in March:
4.2 days - Average snowfall days in April:
1.4 days - Average snowfall days in May:
0 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0.7 days - Average snowfall days in November:
2.2 days - Average snowfall days in December:
7.8 days
The month with the highest number of snowfall days is January (10.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight / Average sunshine
Illinois City, IL
- Average daylight in January:
9h and 4min - Average daylight in February:
10h and 4min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 2min - Average daylight in May:
14h and 3min - Average daylight in June:
15h and 1min
- Average daylight in July:
14h and 5min - Average daylight in August:
13h and 5min - Average daylight in September:
12h and 3min - Average daylight in October:
11h and 1min - Average daylight in November:
9h and 5min - Average daylight in December:
9h and 1min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in January:
4h and 0min - Average sunshine in February:
4h and 1min - Average sunshine in March:
6h and 3min - Average sunshine in April:
7h and 5min - Average sunshine in May:
8h and 5min - Average sunshine in June:
9h and 5min
- Average sunshine in July:
10h and 2min - Average sunshine in August:
9h and 5min - Average sunshine in September:
9h and 2min - Average sunshine in October:
5h and 3min - Average sunshine in November:
5h and 2min - Average sunshine in December:
4h and 2min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days
Illinois City, IL
- Average sunshine days in January:
17.8 days - Average sunshine days in February:
15.5 days - Average sunshine days in March:
17.2 days - Average sunshine days in April:
13.4 days - Average sunshine days in May:
10.9 days - Average sunshine days in June:
10.8 days
- Average sunshine days in July:
11.9 days - Average sunshine days in August:
15.5 days - Average sunshine days in September:
18.5 days - Average sunshine days in October:
17.5 days - Average sunshine days in November:
19.6 days - Average sunshine days in December:
18.6 days
The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is June (10.8 days).
Average UV index
Illinois City, IL
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover
Illinois City, IL
The month with the most cloud cover is January (Cloud cover 57).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility
Illinois City, IL
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).
Illinois City, Illinois, USA
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