Climate and monthly weather forecastSummit, IL
Climate and monthly weather forecast
Weather in January
January, like December, is a freezing cold winter month in Summit, Illinois, with an average temperature varying between 29.5°F (-1.4°C) and 19.2°F (-7.1°C). In Summit, the month of January registers the lowest temperatures, averaging 29.5°F (-1.4°C) at the peak and 19.2°F (-7.1°C) at the lowest. Weather in January »Weather in February
The last month of the winter, February, is a cold month in Summit, Illinois, with an average temperature ranging between max 32.4°F (0.2°C) and min 21.9°F (-5.6°C). The initiation of February records an average high-temperature of a cold 32.4°F (0.2°C), displaying a near consistency with the previous month. Weather in February »Weather in March
March, the first month of the spring in Summit, is a frosty month, with an average temperature varying between 43.7°F (6.5°C) and 32.2°F (0.1°C). March's onset brings a rise in the average high-temperature, moving from a wintry 32.4°F (0.2°C) in February to a frosty 43.7°F (6.5°C). Weather in March »Weather in April
April in Summit, Illinois, is a cool spring month, with temperature in the range of an average low of 40.8°F (4.9°C) and an average high of 54.1°F (12.3°C). With the onset of April, the average high-temperature slightly shifts from March's frosty 43.7°F (6.5°C) to a fresh 54.1°F (12.3°C). Weather in April »Weather in May
May, the last month of the spring in Summit, is a comfortable month, with temperature in the range of an average high of 65.7°F (18.7°C) and an average low of 51.6°F (10.9°C). Observing a rise in May, the average high-temperature goes from April's fresh 54.1°F (12.3°C) to a comfortable 65.7°F (18.7°C). Weather in May »Weather in June
The first month of the summer, June, is a warm month in Summit, Illinois, with an average temperature fluctuating between 61.5°F (16.4°C) and 75.2°F (24°C). The onset of June marks an increase in the average high-temperature, moving from a refreshing 65.7°F (18.7°C) in May to a moderately hot 75.2°F (24°C). Weather in June »Weather in July
July, like June, in Summit, Illinois, is a moderately hot summer month, with an average temperature ranging between min 67.1°F (19.5°C) and max 80.8°F (27.1°C). July is the warmest month of the year, registering average temperatures as high as 80.8°F (27.1°C) and as low as 67.1°F (19.5°C). Throughout July, the heat index is evaluated at a hot 86°F (30°C). Weather in July »Weather in August
The last month of the summer, August, is another warm month in Summit, Illinois, with an average temperature ranging between min 66.4°F (19.1°C) and max 79.2°F (26.2°C). The transition into August reveals an average high-temperature of a still warm 79.2°F (26.2°C), mirroring a close resemblance to July. Weather in August »Weather in September
September, the first month of the autumn in Summit, is also an agreeable month, with an average temperature fluctuating between 72.9°F (22.7°C) and 59.4°F (15.2°C). September heralds a minor drop in average high-temperature, sliding from August's warm 79.2°F (26.2°C) to a pleasant 72.9°F (22.7°C). Weather in September »Weather in October
October, the same as September, in Summit, Illinois, is a moderate autumn month, with an average temperature varying between 60.1°F (15.6°C) and 47.8°F (8.8°C). Summit's average high-temperature decreases in October, falling from an agreeable 72.9°F (22.7°C) in September to a refreshing 60.1°F (15.6°C). Weather in October »Weather in November
November, the last month of the autumn in Summit, is another chilly month, with an average temperature varying between 35.4°F (1.9°C) and 46°F (7.8°C). The onset of November comes with a shift in the average high-temperature, falling from a refreshing 60.1°F (15.6°C) in October to a frosty 46°F (7.8°C). Weather in November »Weather in December
The first month of the winter, December, is also a wintry month in Summit, Illinois, with temperature in the range of an average high of 35.1°F (1.7°C) and an average low of 26.6°F (-3°C). December's arrival correlates with a reduction in the average high-temperature, down from a chilly 46°F (7.8°C) in November to a wintry 35.1°F (1.7°C). Weather in December »Updated: Feb 12, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
January is the month when Summit experiences its coldest temperatures, averaging a high of 29.5°F (-1.4°C) and a low of 19.2°F (-7.1°C).
The months with the highest humidity in Summit, Illinois, are January and February, with an average relative humidity of 82%.
Throughout the year, in Summit, there are 110.8 rainfall days, and 9.61" (244mm) of precipitation is accumulated.
January through April, October through December are months with snowfall in Summit.
Throughout the year, in Summit, there are 32.3 snowfall days, and 4.09" (104mm) of snow is accumulated.
With an average of 3.7h of sunshine, January has the least sunshine of the year in Summit, Illinois.
February is the month with the most snowfall in Summit. Snow falls for 7.5 days and accumulates 1.38" (35mm) of snow.
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.
The month with the most rainfall is May, when the rain falls for 13 days and typically aggregates up to 1.38" (35mm) of precipitation.
In Summit, Illinois, snow does not fall in May through September.
June has the longest days of the year in Summit, with an average of 15h and 12min of daylight.
June through August, with an average maximum UV index of 6, are months with the highest UV index.
With average high and low temperatures of 80.8°F (27.1°C) and 67.1°F (19.5°C) respectively, July is Summit's warmest month.
August has the most sunshine of the year, with an average of 10.6h of sunshine.
October is the least humid month, with an average relative humidity of 72%.
The month with the least rainfall is December, when the rain falls for 5.5 days and typically collects 0.43" (11mm) of precipitation.
With an average of 9h and 12min of daylight, December has the shortest days of the year in Summit, Illinois.
With an average maximum UV index of 1, December is the month with the lowest UV index in Summit.
Average temperature
Summit, IL
The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is January (29.5°F).
The month with the highest average low temperature is July (67.1°F).
The coldest month (with the lowest average low temperature) is January (19.2°F).
Average pressure
Summit, IL
- Average pressure in January:
30.11"Hg - Average pressure in February:
30.1"Hg - Average pressure in March:
30.09"Hg - Average pressure in April:
29.95"Hg - Average pressure in May:
29.96"Hg - Average pressure in June:
29.92"Hg
- Average pressure in July:
29.97"Hg - Average pressure in August:
29.98"Hg - Average pressure in September:
30.03"Hg - Average pressure in October:
30.01"Hg - Average pressure in November:
30.1"Hg - Average pressure in December:
30.09"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed
Summit, IL
- Average wind speed in January:
10.9mph - Average wind speed in February:
10.5mph - Average wind speed in March:
9.9mph - Average wind speed in April:
10.1mph - Average wind speed in May:
8.5mph - Average wind speed in June:
7.6mph
- Average wind speed in July:
6.8mph - Average wind speed in August:
6.7mph - Average wind speed in September:
8mph - Average wind speed in October:
9.8mph - Average wind speed in November:
10.5mph - Average wind speed in December:
10.2mph
The windiest month (with the highest average wind speed) is January (10.9mph).
The calmest month (with the lowest average wind speed) is August (6.7mph).
Average humidity
Summit, IL
The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is October (72%).
Average rainfall
Summit, IL
- Average rainfall in January:
0.51" - Average rainfall in February:
0.47" - Average rainfall in March:
0.47" - Average rainfall in April:
0.91" - Average rainfall in May:
1.38" - Average rainfall in June:
1.22"
- Average rainfall in July:
1.18" - Average rainfall in August:
0.91" - Average rainfall in September:
0.79" - Average rainfall in October:
0.83" - Average rainfall in November:
0.51" - Average rainfall in December:
0.43"
The wettest month (with the highest rainfall) is May (1.38").
The driest month (with the least rainfall) is December (0.43").
Average rainfall days
Summit, IL
- Average rainfall days in January:
4.4 days - Average rainfall days in February:
4.1 days - Average rainfall days in March:
8.8 days - Average rainfall days in April:
12 days - Average rainfall days in May:
13 days - Average rainfall days in June:
13 days
- Average rainfall days in July:
13.3 days - Average rainfall days in August:
11.3 days - Average rainfall days in September:
10.1 days - Average rainfall days in October:
9.4 days - Average rainfall days in November:
5.9 days - Average rainfall days in December:
5.5 days
The month with the highest number of rainy days is July (13.3 days).
The month with the least rainy days is February (4.1 days).
Average snowfall
Summit, IL
The month with the highest snowfall is February (1.38").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days
Summit, IL
- Average snowfall days in January:
10.1 days - Average snowfall days in February:
7.5 days - Average snowfall days in March:
4.3 days - Average snowfall days in April:
1.3 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:
2.5 days - Average snowfall days in December:
6.5 days
The month with the highest number of snowfall days is January (10.1 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight / Average sunshine
Summit, IL
- Average daylight in January:
9h and 36min - Average daylight in February:
10h and 36min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 24min - Average daylight in May:
14h and 36min - Average daylight in June:
15h and 12min
- Average daylight in July:
14h and 54min - Average daylight in August:
13h and 48min - Average daylight in September:
12h and 30min - Average daylight in October:
11h and 6min - Average daylight in November:
9h and 48min - Average daylight in December:
9h and 12min
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 January:
3h and 42min - Average sunshine in February:
3h and 54min - Average sunshine in March:
6h and 12min - Average sunshine in April:
7h and 48min - Average sunshine in May:
8h and 48min - Average sunshine in June:
9h and 54min
- Average sunshine in July:
10h and 30min - Average sunshine in August:
10h and 36min - Average sunshine in September:
9h and 6min - Average sunshine in October:
5h and 54min - Average sunshine in November:
5h and 6min - Average sunshine in December:
4h and 6min
The month with the most sunshine is August (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days
Summit, IL
- Average sunshine days in January:
18.8 days - Average sunshine days in February:
18.1 days - Average sunshine days in March:
18.8 days - Average sunshine days in April:
15.8 days - Average sunshine days in May:
14.1 days - Average sunshine days in June:
12.3 days
- Average sunshine days in July:
12.8 days - Average sunshine days in August:
15.3 days - Average sunshine days in September:
16.9 days - Average sunshine days in October:
18.7 days - Average sunshine days in November:
21.3 days - Average sunshine days in December:
21.2 days
The month with the most sunshine days is November (21.3 days).
The month with the least sunshine days is June (12.3 days).
Average UV index
Summit, IL
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover
Summit, IL
The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility
Summit, 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).
