Climate and monthly weather forecast
Crystal Lake, IL

Share

Weather in January

January, like December, is another subzero cold winter month in Crystal Lake, Illinois, with an average temperature ranging between min 15.1°F (-9.4°C) and max 27°F (-2.8°C). Crystal Lake's January weather, marked by an average high temperature of 27°F (-2.8°C) and an average low temperature of 15.1°F (-9.4°C), is the coldest in the year. Weather in January »

Weather in February

The last month of the winter, February, is also a subzero cold month in Crystal Lake, Illinois, with an average temperature ranging between max 30.6°F (-0.8°C) and min 18°F (-7.8°C). Crystal Lake marks the onset of February with an average high-temperature of a still subzero cold 30.6°F (-0.8°C), subtly divergent from January's 27°F (-2.8°C). Weather in February »

Weather in March

March, the first month of the spring in Crystal Lake, is a chilly month, with an average temperature ranging between max 43.3°F (6.3°C) and min 29.5°F (-1.4°C). As Crystal Lake, Illinois, welcomes March, the average high-temperature sees a rise, transitioning from a subzero cold 30.6°F (-0.8°C) in February to a frosty 43.3°F (6.3°C). Weather in March »

Weather in April

April is a cool spring month in Crystal Lake, Illinois, with an average temperature ranging between min 38.8°F (3.8°C) and max 54.7°F (12.6°C). The average high-temperature increases in April, moving from a frosty 43.3°F (6.3°C) in March to a cool 54.7°F (12.6°C). Weather in April »

Weather in May

The last month of the spring, May, is a comfortable month in Crystal Lake, Illinois, with an average temperature fluctuating between 50°F (10°C) and 67.1°F (19.5°C). A shift in the average high-temperature is noticeable in May, changing from a fresh 54.7°F (12.6°C) in April to a refreshing 67.1°F (19.5°C). Weather in May »

Weather in June

The first month of the summer, June, is a moderately hot month in Crystal Lake, Illinois, with an average temperature fluctuating between 59°F (15°C) and 76.1°F (24.5°C). The arrival of June brings an increase in high-temperatures, moving from an enjoyable 67.1°F (19.5°C) in May to a moderately hot 76.1°F (24.5°C). Weather in June »

Weather in July

July, the same as June, is a moderately hot summer month in Crystal Lake, Illinois, with an average temperature varying between 79.5°F (26.4°C) and 63.1°F (17.3°C). With average high and low temperatures of 79.5°F (26.4°C) and 63.1°F (17.3°C) respectively, July is Crystal Lake's warmest month. Weather in July »

Weather in August

The last month of the summer, August, is another warm month in Crystal Lake, Illinois, with an average temperature ranging between min 61.9°F (16.6°C) and max 78.1°F (25.6°C). The beginning of August records an average high-temperature of a still moderately hot 78.1°F (25.6°C), marking a negligible difference from July's 79.5°F (26.4°C). Weather in August »

Weather in September

The first month of the autumn, September, is still a pleasant month in Crystal Lake, Illinois, with temperature in the range of an average high of 72.5°F (22.5°C) and an average low of 55°F (12.8°C). In Crystal Lake, entering September brings a subtle temperature decrement, reducing from August's moderately hot 78.1°F (25.6°C) to a pleasant 72.5°F (22.5°C). Weather in September »

Weather in October

October, the same as September, in Crystal Lake, Illinois, is a moderate autumn month, with an average temperature ranging between max 59°F (15°C) and min 43.9°F (6.6°C). October's arrival comes with a decrease in the average high-temperature, moving from a pleasant 72.5°F (22.5°C) in September to a refreshing 59°F (15°C). Weather in October »

Weather in November

November, the last month of the autumn in Crystal Lake, is also a frosty month, with an average temperature fluctuating between 44.6°F (7°C) and 31.8°F (-0.1°C). November's arrival sees a clear drop in the average high-temperature, decreasing from October's mild 59°F (15°C) to a frosty 44.6°F (7°C). Weather in November »

Weather in December

The first month of the winter, December, is also an icy month in Crystal Lake, Illinois, with temperature in the range of an average low of 22.8°F (-5.1°C) and an average high of 32.9°F (0.5°C). During the transition into December, Crystal Lake observes a decrease in the average high-temperature, falling from a chilly 44.6°F (7°C) in November to a cold 32.9°F (0.5°C). Weather in December »
Updated: Aug 21, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What time of the year is the coldest?

Crystal Lake, Illinois, reaches its average lowest temperatures in January, measuring 27°F (-2.8°C) at the peak and 15.1°F (-9.4°C) at the lowest.

What is the most humid month?

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

How many days does it rain?

In Crystal Lake, during the entire year, the rain falls for 146.9 days and collects up to 21.22" (539mm) of precipitation.

When does it snow?

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

What is the snowiest month?

January is the month with the most snowfall. Snow falls for 12.5 days and accumulates 3.31" (84mm) of snow.

How much does it snow?

In Crystal Lake, during the entire year, snow falls for 48.7 days and aggregates up to 11.85" (301mm) of snow.

What is the month with the least sunshine?

The month with the least sunshine in Crystal Lake is January, with an average of 3.7h of sunshine.

When is the lowest UV index?

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

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 least humid month?

April and October, with an average relative humidity of 76%, are the least humid months.

What is the rainiest month?

June is the month with the most rainfall. Rain falls for 16.3 days and accumulates 2.8" (71mm) of precipitation.

When it does not snow in Crystal Lake?

In Crystal Lake, snow does not fall in June through September.

When are the longest days?

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

What are the warmest months?

Crystal Lake records the warmest temperatures in July, averaging a high of 79.5°F (26.4°C) and a low of 63.1°F (17.3°C).

What month has the most sunshine?

July has the most sunshine of the year, with an average of 10h of sunshine.

When is the highest UV index in Crystal Lake?

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

What is the driest month?

The months with the least rainfall are November and December Rain falls for 8 days and accumulates 0.94" (24mm) of rain.

What is the month with the shortest days?

December has the shortest days of the year, with an average of 9h and 12min of daylight.

Average temperature
Crystal Lake, IL

Average temperature - Crystal Lake, IL

The warmest month (with the highest average high temperature) is July (79.5°F).
The month with the lowest average high temperature is January (27°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 (15.1°F).

Average pressure
Crystal Lake, IL

Average pressure - Crystal Lake, 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
Crystal Lake, IL

Average wind speed - Crystal Lake, IL

The windiest months (with the highest average wind speed) are January and February (9.9mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).

Average humidity
Crystal Lake, IL

Average humidity - Crystal Lake, IL

The months with the highest relative humidity are January and February (85%).
The months with the lowest relative humidity are April and October (76%).

Average rainfall
Crystal Lake, IL

Average rainfall - Crystal Lake, IL

The wettest month (with the highest rainfall) is June (2.8").
The driest months (with the least rainfall) are November and December (0.94").

Average rainfall days
Crystal Lake, IL

Average rainfall days - Crystal Lake, IL

The month with the highest number of rainy days is July (18.5 days).
The month with the least rainy days is February (4.8 days).

Average snowfall
Crystal Lake, IL

Average snowfall - Crystal Lake, IL

The month with the highest snowfall is January (3.31").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days
Crystal Lake, IL

Average snowfall days - Crystal Lake, IL

The month with the highest number of snowfall days is January (12.5 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight / Average sunshine
Crystal Lake, IL

Average daylight / Average sunshine - Crystal Lake, 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 12min).

The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).

Average sunshine days
Crystal Lake, IL

Average sunshine days - Crystal Lake, IL

The month with the most sunshine days is November (17.3 days).
The month with the least sunshine days is July (10 days).

Average visibility
Crystal Lake, IL

Average visibility - Crystal Lake, IL

The months with the highest visibility are March, April, May, June, July, September, October, November and December (6mi).
The months with the lowest visibility are January, February and August (5mi).

Crystal Lake, Illinois, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location