Climate and monthly weather forecast
McHenry, IL

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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 U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What month is the coldest in McHenry?

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.

What are the most humid months in McHenry?

The months with the highest humidity in McHenry, Illinois, are January and February, with an average relative humidity of 85%.

How much does it rain in McHenry?

In McHenry, during the entire year, the rain falls for 152.4 days and collects up to 28.07" (713mm) of precipitation.

When does it snow in McHenry?

Months with snowfall are January through May, October through December.

When does it snow the most in McHenry?

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.

How many days does it snow in McHenry?

In McHenry, Illinois, during the entire year, snow falls for 49 days and aggregates up to 16.5" (419mm) of snow.

What is the month with the least sunshine in McHenry?

With an average of 3.7h of sunshine, January has the least sunshine of the year in McHenry.

What is the month with the lowest UV index in McHenry?

The months with the lowest UV index are January and December, with an average maximum UV index of 1.

When is Daylight Saving Time (DST) in McHenry?

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 McHenry?

June is the month with the most rainfall in McHenry. Rain falls for 17.2 days and accumulates 3.58" (91mm) of precipitation.

When it does not snow in McHenry?

In McHenry, Illinois, snow does not fall in June through September.

When are the longest days in McHenry?

The month with the longest days is June, with an average of 15h and 12min of daylight.

What is the warmest month in McHenry?

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).

What are the months with the most sunshine in McHenry?

The months with the most sunshine are July and August, with an average of 10h of sunshine.

What is the month with the highest UV index in McHenry?

With an average maximum UV index of 6, August is the month with the highest UV index in McHenry, Illinois.

What is the least humid month in McHenry?

October is the least humid month, with an average relative humidity of 76%.

What is the driest month in McHenry?

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.

What is the month with the shortest days in McHenry?

December has the shortest days of the year, with an average of 9h and 6min of daylight.

Average temperature
McHenry, IL

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 - McHenry, IL

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 - McHenry, IL

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

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 - McHenry, IL

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 - McHenry, IL

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 - McHenry, IL

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 - McHenry, IL

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 / Average sunshine - McHenry, IL

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).

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 - McHenry, IL

The month with the most sunshine days is November (16 days).
The month with the least sunshine days is June (10.2 days).

Average visibility
McHenry, IL

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).

McHenry, Illinois, USA

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