Climate and monthly weather forecastMcHenry, IL
Climate and monthly weather forecast
Weather in January
January, the same as December, in McHenry, Illinois, is a freezing cold winter month, with an average temperature ranging between max 26.6°F (-3°C) and min 14.9°F (-9.5°C). In McHenry, January records the lowest average temperatures, peaking at 26.6°F (-3°C) and reaching a low of 14.9°F (-9.5°C). Weather in January »Weather in February
The last month of the winter, February, is also a subzero cold month in McHenry, Illinois, with an average temperature ranging between max 30.2°F (-1°C) and min 18°F (-7.8°C). McHenry marks the start of February with an average high-temperature of a still subzero cold 30.2°F (-1°C), hinting at a slight fluctuation from January's 26.6°F (-3°C). Weather in February »Weather in March
The first month of the spring, March, is a frosty month in McHenry, Illinois, with an average temperature fluctuating between 42.8°F (6°C) and 28.9°F (-1.7°C). As McHenry, Illinois, transitions into March, a rise in the average high-temperature is observed, moving from a subzero cold 30.2°F (-1°C) in February to a chilly 42.8°F (6°C). Weather in March »Weather in April
April in McHenry, Illinois, is a cool spring month, with an average temperature varying between 54.3°F (12.4°C) and 38.3°F (3.5°C). The start of April brings a shift in the average high-temperature, increasing from March's frosty 42.8°F (6°C) to a fresh 54.3°F (12.4°C). Weather in April »Weather in May
The last month of the spring, May, is a comfortable month in McHenry, Illinois, with an average temperature fluctuating between 66.4°F (19.1°C) and 49.3°F (9.6°C). With the onset of May, McHenry sees a temperature rise, with the average high-temperature moving from April's cool 54.3°F (12.4°C) to a refreshing 66.4°F (19.1°C). Weather in May »Weather in June
June, the first month of the summer in McHenry, is a moderately hot month, with an average temperature fluctuating between 75.6°F (24.2°C) and 58.5°F (14.7°C). June marks a rise in the average high-temperature, moving from May's comfortable 66.4°F (19.1°C) to a warm 75.6°F (24.2°C). Weather in June »Weather in July
July, like June, in McHenry, Illinois, is a moderately hot summer month, with an average temperature fluctuating between 79.7°F (26.5°C) and 63.1°F (17.3°C). In McHenry, the peak average temperatures are observed in July, with a high of 79.7°F (26.5°C) and a low of 63.1°F (17.3°C). Weather in July »Weather in August
The last month of the summer, August, is another warm month in McHenry, Illinois, with an average temperature fluctuating between 61.3°F (16.3°C) and 78.1°F (25.6°C). McHenry, Illinois, experiences an average high-temperature of a still warm 78.1°F (25.6°C) with the onset of August, subtly varied from July's 79.7°F (26.5°C). Weather in August »Weather in September
September, the first month of the autumn in McHenry, is also an agreeable month, with an average temperature varying between 55°F (12.8°C) and 72.3°F (22.4°C). A moderate decline in average high-temperatures is noted in September, moving from a warm 78.1°F (25.6°C) in August to an agreeable 72.3°F (22.4°C). Weather in September »Weather in October
October, like September, is another refreshing autumn month in McHenry, Illinois, with an average temperature varying between 58.6°F (14.8°C) and 43.9°F (6.6°C). Transition from September to October is accompanied by a temperature drop, with average high-temperatures decreasing from an agreeable 72.3°F (22.4°C) to a refreshing 58.6°F (14.8°C). Weather in October »Weather in November
The last month of the autumn, November, is another chilly month in McHenry, Illinois, with temperature in the range of an average low of 32.2°F (0.1°C) and an average high of 44.6°F (7°C). November brings a decrease in the average high-temperature, shifting from a mild 58.6°F (14.8°C) in October to a chilly 44.6°F (7°C). Weather in November »Weather in December
The first month of the winter, December, is also a wintry month in McHenry, Illinois, with an average temperature varying between 32.7°F (0.4°C) and 22.8°F (-5.1°C). The average high-temperature decreases in December, shifting from a frosty 44.6°F (7°C) in November to a wintry 32.7°F (0.4°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
With its average high temperature of 26.6°F (-3°C) and a low of 14.9°F (-9.5°C), January is regarded as the coldest month.
The months with the highest humidity in McHenry, Illinois, are January and February, with an average relative humidity of 85%.
In McHenry, during the entire year, the rain falls for 152.4 days and collects up to 28.07" (713mm) of precipitation.
Months with snowfall are January through May, October through December.
The month with the most snowfall in McHenry is January, when snow falls for 13.3 days and typically aggregates up to 5.16" (131mm) of snow.
In McHenry, Illinois, during the entire year, snow falls for 49 days and aggregates up to 16.5" (419mm) of snow.
With an average of 3.7h of sunshine, January has the least sunshine of the year in McHenry.
The months with the lowest UV index are January and December, with an average maximum UV index of 1.
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.
June is the month with the most rainfall in McHenry. Rain falls for 17.2 days and accumulates 3.58" (91mm) of precipitation.
In McHenry, Illinois, snow does not fall in June through September.
The month with the longest days is June, with an average of 15h and 12min of daylight.
The warmest period in McHenry tends to be July, when average temperatures fluctuate between a high of 79.7°F (26.5°C) and a low of 63.1°F (17.3°C).
The months with the most sunshine are July and August, with an average of 10h of sunshine.
With an average maximum UV index of 6, August is the month with the highest UV index in McHenry, Illinois.
October is the least humid month, with an average relative humidity of 76%.
The month with the least rainfall in McHenry is December, when the rain falls for 7.9 days and typically collects 1.34" (34mm) of precipitation.
December has the shortest days of the year, with an average of 9h and 6min of daylight.
Average temperature
McHenry, IL
The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is January (26.6°F).
The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (14.9°F).
Average pressure
McHenry, 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:
29.97"Hg - Average pressure in September:
30.03"Hg - Average pressure in October:
30"Hg - Average pressure in November:
30.09"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
McHenry, IL
- Average wind speed in January:
10mph - Average wind speed in February:
9.9mph - Average wind speed in March:
9.6mph - Average wind speed in April:
9.8mph - Average wind speed in May:
8.3mph - Average wind speed in June:
7.2mph
- Average wind speed in July:
6.4mph - Average wind speed in August:
6.2mph - Average wind speed in September:
7.3mph - Average wind speed in October:
8.8mph - Average wind speed in November:
9.5mph - Average wind speed in December:
9.3mph
The windiest month (with the highest average wind speed) is January (10mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).
Average humidity
McHenry, IL
The months with the highest relative humidity are January and February (85%).
The month with the lowest relative humidity is October (76%).
Average rainfall
McHenry, IL
- Average rainfall in January:
1.54" - Average rainfall in February:
1.46" - Average rainfall in March:
1.77" - Average rainfall in April:
3.46" - Average rainfall in May:
3.39" - Average rainfall in June:
3.58"
- Average rainfall in July:
2.87" - Average rainfall in August:
2.56" - Average rainfall in September:
2.09" - Average rainfall in October:
2.52" - Average rainfall in November:
1.5" - Average rainfall in December:
1.34"
The wettest month (with the highest rainfall) is June (3.58").
The driest month (with the least rainfall) is December (1.34").
Average rainfall days
McHenry, IL
- Average rainfall days in January:
5.6 days - Average rainfall days in February:
4.9 days - Average rainfall days in March:
11.1 days - Average rainfall days in April:
16.8 days - Average rainfall days in May:
17.8 days - Average rainfall days in June:
17.2 days
- Average rainfall days in July:
18.3 days - Average rainfall days in August:
16.1 days - Average rainfall days in September:
13.5 days - Average rainfall days in October:
14 days - Average rainfall days in November:
9.2 days - Average rainfall days in December:
7.9 days
The month with the highest number of rainy days is July (18.3 days).
The month with the least rainy days is February (4.9 days).
Average snowfall
McHenry, IL
- Average snowfall in January:
5.16" - Average snowfall in February:
3.5" - Average snowfall in March:
1.89" - Average snowfall in April:
1.54" - Average snowfall in May:
0.08" - Average snowfall in June:
0"
The month with the highest snowfall is January (5.16").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days
McHenry, IL
- Average snowfall days in January:
13.3 days - Average snowfall days in February:
11.3 days - Average snowfall days in March:
6.8 days - Average snowfall days in April:
2.2 days - Average snowfall days in May:
0.1 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:
0.5 days - Average snowfall days in November:
4.5 days - Average snowfall days in December:
10.3 days
The month with the highest number of snowfall days is January (13.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight / Average sunshine
McHenry, IL
- Average daylight in January:
9h and 30min - 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 0min - Average daylight in November:
9h and 48min - Average daylight in December:
9h and 6min
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 6min).
- Average sunshine in January:
3h and 42min - Average sunshine in February:
3h and 48min - Average sunshine in March:
6h and 6min - Average sunshine in April:
7h and 30min - Average sunshine in May:
8h and 30min - Average sunshine in June:
9h and 42min
- Average sunshine in July:
10h and 0min - Average sunshine in August:
10h and 0min - Average sunshine in September:
8h and 54min - Average sunshine in October:
5h and 30min - Average sunshine in November:
5h and 6min - Average sunshine in December:
4h and 0min
The months with the most sunshine are July and August (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days
McHenry, IL
- Average sunshine days in January:
13.7 days - Average sunshine days in February:
12.1 days - Average sunshine days in March:
14.4 days - Average sunshine days in April:
10.5 days - Average sunshine days in May:
11 days - Average sunshine days in June:
10.2 days
- Average sunshine days in July:
10.9 days - Average sunshine days in August:
12.4 days - Average sunshine days in September:
14.3 days - Average sunshine days in October:
14.5 days - Average sunshine days in November:
16 days - Average sunshine days in December:
15.9 days
The month with the most sunshine days is November (16 days).
The month with the least sunshine days is June (10.2 days).
Average UV index
McHenry, IL
The month with the highest UV index is August (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover
McHenry, IL
The month with the most cloud cover is January (Cloud cover 62).
The months with the least cloud cover are August and September (Cloud cover 31).
Average visibility
McHenry, IL
The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and February (5mi).
