Expand
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, the same as December, is a wintry winter month in Chester, Illinois, with an average temperature ranging between max 39.6°F (4.2°C) and min 25.7°F (-3.5°C). January proves to be the coldest month, recording an average maximum temperature of 39.6°F (4.2°C) and a minimum temperature of 25.7°F (-3.5°C). Weather in January »
Weather in February
The last month of the winter, February, is a chilly month in Chester, Illinois, with temperature in the range of an average low of 29.1°F (-1.6°C) and an average high of 43.7°F (6.5°C). A minimal variation is noted in Chester's average high-temperature at the onset of February, reaching a chilly 43.7°F (6.5°C) from January's 39.6°F (4.2°C). Weather in February »
Weather in March
The first month of the spring, March, is a refreshing month in Chester, Illinois, with an average temperature fluctuating between 38.8°F (3.8°C) and 55.4°F (13°C). With the onset of March, Chester's average high-temperature experiences a rise, moving from February's chilly 43.7°F (6.5°C) to a mild 55.4°F (13°C). Weather in March »
Weather in April
April in Chester, Illinois, is an enjoyable spring month, with an average temperature ranging between min 48°F (8.9°C) and max 66.4°F (19.1°C). In Chester, the average high-temperature in April rises, from a mild 55.4°F (13°C) in March, to an enjoyable 66.4°F (19.1°C). Weather in April »
Weather in May
May, the last month of the spring in Chester, is a warm month, with an average temperature fluctuating between 75.7°F (24.3°C) and 57.9°F (14.4°C). May's onset witnesses a shift in the average high-temperature, moving from a refreshing 66.4°F (19.1°C) in April to a moderately hot 75.7°F (24.3°C). Weather in May »
Weather in June
The first month of the summer, June, is still a warm month in Chester, Illinois, with an average temperature ranging between max 85.1°F (29.5°C) and min 66.6°F (19.2°C). June indicates a change in the average high-temperature, moving up from 75.7°F (24.3°C) in May to a still moderately hot 85.1°F (29.5°C). Weather in June »
Weather in July
July is a tropical summer month in Chester, Illinois, with an average temperature ranging between max 87.4°F (30.8°C) and min 68.5°F (20.3°C). July, with an average high of 87.4°F (30.8°C) and a low of 68.5°F (20.3°C), signifies the warmest month of the year. The heat index for July is appraised at a very hot 102.2°F (39°C). Weather in July »
Weather in August
The last month of the summer, August, is also a moderately hot month in Chester, Illinois, with an average temperature fluctuating between 66.2°F (19°C) and 85.8°F (29.9°C). Chester records an average high-temperature of a warm 85.8°F (29.9°C) in August, closely mirroring the climate of the previous month. Weather in August »
Weather in September
September, the first month of the autumn in Chester, is still a warm month, with temperature in the range of an average high of 79.9°F (26.6°C) and an average low of 60.1°F (15.6°C). The start of September comes with a small reduction in the average high-temperature, subtly receding from 85.8°F (29.9°C) in August to a still moderately hot 79.9°F (26.6°C). Weather in September »
Weather in October
October, like September, in Chester, Illinois, is another enjoyable autumn month, with an average temperature varying between 49.1°F (9.5°C) and 67.1°F (19.5°C). October brings a minor decrease, with the average high-temperature reducing from a moderately hot 79.9°F (26.6°C) in September to a refreshing 67.1°F (19.5°C). Weather in October »
Weather in November
The last month of the autumn, November, is also a fresh month in Chester, Illinois, with an average temperature ranging between min 38.7°F (3.7°C) and max 53.8°F (12.1°C). In Chester, the average high-temperature in November decreases from an enjoyable 67.1°F (19.5°C) in October to a cool 53.8°F (12.1°C). Weather in November »
Weather in December
December, the first month of the winter in Chester, is still a chilly month, with temperature in the range of an average high of 43.7°F (6.5°C) and an average low of 31.1°F (-0.5°C). Chester's transition into December involves a shift in temperature, receding from a cool 53.8°F (12.1°C) in November to a frosty 43.7°F (6.5°C). Weather in December »
Updated: Jun 23, 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 time of the year is the coldest?
With its average high temperature of 39.6°F (4.2°C) and a low of 25.7°F (-3.5°C), January is regarded as the coldest month.
How many days does it rain?
Throughout the year, there are 156.4 rainfall days, and 34.25" (870mm) of precipitation is accumulated.
When does it snow?
January through April, October through December are months with snowfall.
How much does it snow?
In Chester, during the entire year, snow falls for 16 days and aggregates up to 6.89" (175mm) of snow.
What is the month with the least sunshine?
With an average of 4.7h of sunshine, January has the least sunshine of the year.
When is the lowest UV index?
January, February and December, with an average maximum UV index of 2, are months with the lowest UV index.
When does it snow the most?
The month with the most snowfall is February, when snow falls for 5.2 days and typically aggregates up to 2.56" (65mm) 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 rainiest month?
April is the month with the most rainfall. Rain falls for 15.6 days and accumulates 4.13" (105mm) of precipitation.
What is the most humid month?
The most humid month is May, with an average relative humidity of 79%.
When it does not snow?
May through September are months without snowfall.
What are the months with the highest UV index?
May through August, with an average maximum UV index of 6, are months with the highest UV index.
When are the longest days?
The month with the longest days is June, with an average of 14h and 48min of daylight.
What is the month with the most sunshine in Chester?
The months with the most sunshine are June and July, with an average of 10.5h of sunshine.
What are the warmest months?
The average temperatures reach their apex in July, averaging 87.4°F (30.8°C) at the high end and 68.5°F (20.3°C) at the low end.
What is the driest month?
The month with the least rainfall is September, when the rain falls for 13 days and typically collects 1.97" (50mm) of precipitation.
What is the least humid month?
The least humid month is October, with an average relative humidity of 71%.
What is the month with the shortest days?
December has the shortest days of the year, with an average of 9h and 36min of daylight.
Average temperature
Chester, IL
The warmest month (with the highest average high temperature) is July (87.4°F).
The month with the lowest average high temperature is January (39.6°F).
The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (25.7°F).
Average pressure
Chester, IL
- Average pressure in January:
30.16"Hg - Average pressure in February:
30.12"Hg - Average pressure in March:
30.07"Hg - Average pressure in April:
29.95"Hg - Average pressure in May:
29.96"Hg - Average pressure in June:
29.93"Hg
- Average pressure in July:
29.97"Hg - Average pressure in August:
29.98"Hg - Average pressure in September:
30.02"Hg - Average pressure in October:
30.04"Hg - Average pressure in November:
30.13"Hg - Average pressure in December:
30.14"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed
Chester, IL
- Average wind speed in January:
9.4mph - Average wind speed in February:
9.2mph - Average wind speed in March:
9.1mph - Average wind speed in April:
8.9mph - Average wind speed in May:
7.4mph - Average wind speed in June:
6.4mph
- Average wind speed in July:
5.6mph - Average wind speed in August:
5.5mph - Average wind speed in September:
6mph - Average wind speed in October:
7.7mph - Average wind speed in November:
8.4mph - Average wind speed in December:
8.6mph
The windiest month (with the highest average wind speed) is January (9.4mph).
The calmest month (with the lowest average wind speed) is August (5.5mph).
Average humidity
Chester, IL
The month with the highest relative humidity is May (79%).
The month with the lowest relative humidity is October (71%).
Average rainfall
Chester, IL
- Average rainfall in January:
2.13" - Average rainfall in February:
2.01" - Average rainfall in March:
2.95" - Average rainfall in April:
4.13" - Average rainfall in May:
3.86" - Average rainfall in June:
3.27"
- Average rainfall in July:
3.19" - Average rainfall in August:
3.19" - Average rainfall in September:
1.97" - Average rainfall in October:
2.87" - Average rainfall in November:
2.28" - Average rainfall in December:
2.4"
The wettest month (with the highest rainfall) is April (4.13").
The driest month (with the least rainfall) is September (1.97").
Average rainfall days
Chester, IL
- Average rainfall days in January:
7.9 days - Average rainfall days in February:
9.3 days - Average rainfall days in March:
15.1 days - Average rainfall days in April:
15.6 days - Average rainfall days in May:
17.3 days - Average rainfall days in June:
15.7 days
- Average rainfall days in July:
17.8 days - Average rainfall days in August:
14.9 days - Average rainfall days in September:
13 days - Average rainfall days in October:
10.5 days - Average rainfall days in November:
10.2 days - Average rainfall days in December:
9.1 days
The month with the highest number of rainy days is July (17.8 days).
The month with the least rainy days is January (7.9 days).
Average snowfall
Chester, IL
The month with the highest snowfall is February (2.56").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days
Chester, IL
- Average snowfall days in January:
4.8 days - Average snowfall days in February:
5.2 days - Average snowfall days in March:
1.3 days - Average snowfall days in April:
0.3 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:
0.1 days - Average snowfall days in November:
1.3 days - Average snowfall days in December:
3 days
The month with the highest number of snowfall days is February (5.2 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight / Average sunshine
Chester, IL
- Average daylight in January:
9h and 5min - Average daylight in February:
10h and 5min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 1min - Average daylight in May:
14h and 1min - Average daylight in June:
14h and 5min
- Average daylight in July:
14h and 3min - Average daylight in August:
13h and 4min - Average daylight in September:
12h and 2min - Average daylight in October:
11h and 1min - Average daylight in November:
10h and 1min - Average daylight in December:
9h and 4min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in January:
4h and 4min - Average sunshine in February:
4h and 5min - Average sunshine in March:
6h and 3min - Average sunshine in April:
8h and 4min - Average sunshine in May:
9h and 2min - Average sunshine in June:
10h and 3min
- Average sunshine in July:
10h and 3min - Average sunshine in August:
10h and 1min - Average sunshine in September:
9h and 2min - Average sunshine in October:
6h and 2min - Average sunshine in November:
5h and 4min - Average sunshine in December:
5h and 0min
The months with the most sunshine are June and July (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 42min).
Average sunshine days
Chester, IL
- Average sunshine days in January:
18.8 days - Average sunshine days in February:
13.8 days - Average sunshine days in March:
13.6 days - Average sunshine days in April:
12.6 days - Average sunshine days in May:
11.3 days - Average sunshine days in June:
12 days
- Average sunshine days in July:
9.8 days - Average sunshine days in August:
13 days - Average sunshine days in September:
15.4 days - Average sunshine days in October:
18.9 days - Average sunshine days in November:
18.5 days - Average sunshine days in December:
18.7 days
The month with the most sunshine days is October (18.9 days).
The month with the least sunshine days is July (9.8 days).
Average UV index
Chester, IL
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February and December (UV index 2).
Average cloud cover
Chester, IL
The months with the most cloud cover are January and February (Cloud cover 48).
The month with the least cloud cover is June (Cloud cover 27).
Average visibility
Chester, 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).
Chester, Illinois, USA
Weather forecast for your location
1. Click Locate me button
2. Allow the app to use your location
2. Allow the app to use your location