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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 another subzero cold winter month in McLean, Illinois, with an average temperature ranging between min 19.8°F (-6.8°C) and max 31.6°F (-0.2°C). January is the coldest month, exhibiting average temperatures of 31.6°F (-0.2°C) at the peak and 19.8°F (-6.8°C) at the base. Weather in January »
Weather in February
February, the last month of the winter in McLean, is a cold month, with an average temperature fluctuating between 23.5°F (-4.7°C) and 36.7°F (2.6°C). The advent of February sees the average high-temperature at a wintry 36.7°F (2.6°C), subtly shifted from January's 31.6°F (-0.2°C). Weather in February »
Weather in March
March, the first month of the spring in McLean, is a chilly month, with an average temperature varying between 49.5°F (9.7°C) and 34.7°F (1.5°C). The shift into March is accompanied by a temperature increase, with the average high-temperature rising from an icy 36.7°F (2.6°C) in February to a chilly 49.5°F (9.7°C). Weather in March »
Weather in April
April in McLean, Illinois, is a comfortable spring month, with an average temperature fluctuating between 61.3°F (16.3°C) and 45.1°F (7.3°C). McLean in April shows a temperature shift, moving from an average high of a frosty 49.5°F (9.7°C) in March to a comfortable 61.3°F (16.3°C). Weather in April »
Weather in May
May, the last month of the spring in McLean, is an agreeable month, with an average temperature varying between 55.8°F (13.2°C) and 72.1°F (22.3°C). The shift into May brings an increase in the average high-temperature, moving from a comfortable 61.3°F (16.3°C) in April to a pleasant 72.1°F (22.3°C). Weather in May »
Weather in June
June, the first month of the summer in McLean, is a warm month, with temperature in the range of an average high of 80.1°F (26.7°C) and an average low of 63.9°F (17.7°C). A soft shift in the average high-temperature is noticeable in June, transitioning from an agreeable 72.1°F (22.3°C) in May to a warm 80.1°F (26.7°C). Weather in June »
Weather in July
July, like June, in McLean, Illinois, is a moderately hot summer month, with an average temperature fluctuating between 65.1°F (18.4°C) and 81.5°F (27.5°C). In McLean, the highest average temperatures are observed in July, with a high of 81.5°F (27.5°C) and a low of 65.1°F (18.4°C). The heat index value for July is calculated to be a hot 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 McLean, Illinois, with an average temperature fluctuating between 63.5°F (17.5°C) and 81.1°F (27.3°C). The arrival of August brings an average high-temperature of a still moderately hot 81.1°F (27.3°C), subtly diverging from July's 81.5°F (27.5°C). Weather in August »
Weather in September
The first month of the autumn, September, is still a warm month in McLean, Illinois, with an average temperature ranging between max 76.1°F (24.5°C) and min 58.3°F (14.6°C). September observes an average high-temperature of a still moderately hot 76.1°F (24.5°C), marking an insignificant difference from August's 81.1°F (27.3°C). Weather in September »
Weather in October
October, the same as September, is another refreshing autumn month in McLean, Illinois, with an average temperature fluctuating between 46.9°F (8.3°C) and 63.3°F (17.4°C). The average high-temperature decreases in October, shifting from a warm 76.1°F (24.5°C) in September to a comfortable 63.3°F (17.4°C). Weather in October »
Weather in November
The last month of the autumn, November, is also a frosty month in McLean, Illinois, with an average temperature fluctuating between 49.1°F (9.5°C) and 35.4°F (1.9°C). The arrival of November indicates a decrease in the average high-temperature, moving from a comfortable 63.3°F (17.4°C) in October to a frosty 49.1°F (9.5°C). Weather in November »
Weather in December
December, the first month of the winter in McLean, is also an icy month, with temperature in the range of an average low of 27°F (-2.8°C) and an average high of 37.4°F (3°C). With December's arrival, McLean's weather changes as the average high-temperature falls from a chilly 49.1°F (9.5°C) in November to a wintry 37.4°F (3°C). Weather in December »
Updated: Feb 12, 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 are the coldest months in McLean?
In McLean, January is known for its average lowest temperatures, reaching a high of 31.6°F (-0.2°C) and a low of 19.8°F (-6.8°C).
How much does it rain in McLean?
In McLean, during the entire year, the rain falls for 135 days and collects up to 17.72" (450mm) of precipitation.
When does it snow in McLean?
Months with snowfall are January through April, November and December.
What is the snowiest month in McLean?
The month with the most snowfall in McLean, Illinois, is January, when snow falls for 9.5 days and typically aggregates up to 2.2" (56mm) of snow.
How many days does it snow in McLean?
In McLean, during the entire year, snow falls for 27.1 days and aggregates up to 7.2" (183mm) of snow.
What is the month with the least sunshine in McLean?
January has the least sunshine of the year in McLean, with an average of 4h of sunshine.
What are the months with the lowest UV index in McLean?
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2.
When is Daylight Saving Time (DST) in McLean?
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 in McLean?
May is the month with the most rainfall. Rain falls for 16.5 days and accumulates 2.2" (56mm) of precipitation.
When it does not snow in McLean?
May through October are months without snowfall in McLean, Illinois.
When are the longest days in McLean?
June has the longest days of the year, with an average of 15h and 0min of daylight.
What month has the most sunshine in McLean?
June has the most sunshine of the year in McLean, Illinois, with an average of 10.3h of sunshine.
What are the months with the highest UV index in McLean?
June through August, with an average maximum UV index of 6, are months with the highest UV index in McLean.
What is the hottest time of year in McLean?
July is the month that records the highest temperatures in McLean, Illinois, with averages ranging from a high of 81.5°F (27.5°C) to a low of 65.1°F (18.4°C).
What is the most humid month in McLean?
July is the most humid month, with an average relative humidity of 85%.
What is the least humid month in McLean?
The least humid month in McLean, Illinois, is October, with an average relative humidity of 70%.
What is the driest month in McLean?
December is the month with the least rainfall in McLean. Rain falls for 7.2 days and accumulates 0.87" (22mm) of precipitation.
What is the month with the shortest days in McLean?
With an average of 9h and 24min of daylight, December has the shortest days of the year in McLean.
Average temperature
McLean, IL
The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (31.6°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 (19.8°F).
Average pressure
McLean, 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:
29.94"Hg - Average pressure in May:
29.95"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:
30.02"Hg - Average pressure in November:
30.11"Hg - Average pressure in December:
30.12"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
McLean, IL
- Average wind speed in January:
10.5mph - Average wind speed in February:
10.5mph - Average wind speed in March:
10.3mph - Average wind speed in April:
10.6mph - Average wind speed in May:
8.9mph - Average wind speed in June:
7.7mph
- Average wind speed in July:
6.5mph - Average wind speed in August:
6.3mph - Average wind speed in September:
7.5mph - Average wind speed in October:
9.3mph - Average wind speed in November:
10mph - Average wind speed in December:
9.9mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.3mph).
Average humidity
McLean, IL
The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (70%).
Average rainfall
McLean, IL
- Average rainfall in January:
0.98" - Average rainfall in February:
0.98" - Average rainfall in March:
1.38" - Average rainfall in April:
1.93" - Average rainfall in May:
2.2" - Average rainfall in June:
2.17"
- Average rainfall in July:
1.69" - Average rainfall in August:
1.65" - Average rainfall in September:
1.46" - Average rainfall in October:
1.34" - Average rainfall in November:
1.06" - Average rainfall in December:
0.87"
The wettest month (with the highest rainfall) is May (2.2").
The driest month (with the least rainfall) is December (0.87").
Average rainfall days
McLean, IL
- Average rainfall days in January:
6.6 days - Average rainfall days in February:
5.9 days - Average rainfall days in March:
11.8 days - Average rainfall days in April:
14 days - Average rainfall days in May:
16.5 days - Average rainfall days in June:
14.8 days
- Average rainfall days in July:
15.8 days - Average rainfall days in August:
13.3 days - Average rainfall days in September:
11.4 days - Average rainfall days in October:
9.8 days - Average rainfall days in November:
7.9 days - Average rainfall days in December:
7.2 days
The month with the highest number of rainy days is May (16.5 days).
The month with the least rainy days is February (5.9 days).
Average snowfall
McLean, IL
The month with the highest snowfall is January (2.2").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days
McLean, IL
- Average snowfall days in January:
9.5 days - Average snowfall days in February:
6.2 days - Average snowfall days in March:
3 days - Average snowfall days in April:
0.8 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:
0.2 days - Average snowfall days in November:
2.1 days - Average snowfall days in December:
5.3 days
The month with the highest number of snowfall days is January (9.5 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight / Average sunshine
McLean, 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 2min - Average daylight in June:
15h and 0min
- Average daylight in July:
14h and 4min - 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 0min - Average daylight in December:
9h 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 January:
4h and 0min - Average sunshine in February:
4h and 2min - Average sunshine in March:
6h and 3min - Average sunshine in April:
8h and 1min - Average sunshine in May:
9h and 2min - Average sunshine in June:
10h and 2min
- Average sunshine in July:
10h and 0min - Average sunshine in August:
9h and 5min - Average sunshine in September:
9h and 1min - Average sunshine in October:
6h and 0min - Average sunshine in November:
5h and 2min - Average sunshine in December:
4h and 3min
The month with the most sunshine is June (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days
McLean, IL
- Average sunshine days in January:
18.8 days - Average sunshine days in February:
16.8 days - Average sunshine days in March:
16.3 days - Average sunshine days in April:
14 days - Average sunshine days in May:
11.6 days - Average sunshine days in June:
12.3 days
- Average sunshine days in July:
11.8 days - Average sunshine days in August:
14.3 days - Average sunshine days in September:
17.1 days - Average sunshine days in October:
19.5 days - Average sunshine days in November:
20 days - Average sunshine days in December:
20 days
The months with the most sunshine days are November and December (20 days).
The month with the least sunshine days is May (11.6 days).
Average UV index
McLean, IL
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
McLean, IL
The month with the most cloud cover is January (Cloud cover 57).
The month with the least cloud cover is September (Cloud cover 30).
Average visibility
McLean, IL
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).
McLean, Illinois, USA
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