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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 a freezing cold winter month in Grayslake, Illinois, with temperature in the range of an average low of 16.5°F (-8.6°C) and an average high of 27.5°F (-2.5°C). January, known for its average high temperature of 27.5°F (-2.5°C) and an average low temperature of 16.5°F (-8.6°C), is the coldest month. Weather in January »
Weather in February
February, the last month of the winter in Grayslake, is also a subzero cold month, with an average temperature fluctuating between 18.7°F (-7.4°C) and 30.6°F (-0.8°C). Grayslake experiences a minor change to a still freezing cold 30.6°F (-0.8°C) in average high-temperature during February, closely reflecting January. Weather in February »
Weather in March
The first month of the spring, March, is a chilly month in Grayslake, Illinois, with an average temperature ranging between min 30.2°F (-1°C) and max 42.8°F (6°C). Noticing a change, the average high-temperature during March moves from February's subzero cold 30.6°F (-0.8°C) to a frosty 42.8°F (6°C). Weather in March »
Weather in April
April in Grayslake, Illinois, is a cool spring month, with an average temperature ranging between max 53.6°F (12°C) and min 38.8°F (3.8°C). April brings a rise in the average high-temperature, transitioning from March's frosty 42.8°F (6°C) to a cool 53.6°F (12°C). Weather in April »
Weather in May
The last month of the spring, May, is an enjoyable month in Grayslake, Illinois, with temperature in the range of an average high of 65.3°F (18.5°C) and an average low of 49.6°F (9.8°C). Grayslake's May weather brings a rise in high-temperatures, moving from a cool 53.6°F (12°C) in April to a refreshing 65.3°F (18.5°C). Weather in May »
Weather in June
The first month of the summer, June, is a warm month in Grayslake, Illinois, with temperature in the range of an average low of 58.8°F (14.9°C) and an average high of 74.8°F (23.8°C). With the beginning of June, Grayslake's average high-temperature sees an increase, transitioning from an enjoyable 65.3°F (18.5°C) in May to a moderately hot 74.8°F (23.8°C). Weather in June »
Weather in July
July, the same as June, is another warm summer month in Grayslake, Illinois, with an average temperature fluctuating between 79.9°F (26.6°C) and 64.4°F (18°C). In Grayslake, temperatures reach their average annual highs in July, measuring 79.9°F (26.6°C) and a minimum average of 64.4°F (18°C). Weather in July »
Weather in August
August, the last month of the summer in Grayslake, is also a moderately hot month, with an average temperature varying between 78.6°F (25.9°C) and 63.1°F (17.3°C). The transition into August notes an average high-temperature of a still moderately hot 78.6°F (25.9°C), revealing a mild distinction from the 79.9°F (26.6°C) in July. Weather in August »
Weather in September
September, the first month of the autumn in Grayslake, is also an agreeable month, with an average temperature fluctuating between 72.3°F (22.4°C) and 57°F (13.9°C). In September, the meteorological conditions change slightly, with the average high-temperature moving from a moderately hot 78.6°F (25.9°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 Grayslake, Illinois, with temperature in the range of an average high of 59°F (15°C) and an average low of 45.1°F (7.3°C). The start of October comes with a reduction in the average high-temperature, receding from a pleasant 72.3°F (22.4°C) in September to a moderate 59°F (15°C). Weather in October »
Weather in November
November, the last month of the autumn in Grayslake, is also a frosty month, with an average temperature fluctuating between 45.1°F (7.3°C) and 32.9°F (0.5°C). The beginning of November marks a decrease in the average high-temperature, transitioning from a mild 59°F (15°C) in October to a chilly 45.1°F (7.3°C). Weather in November »
Weather in December
December, the first month of the winter in Grayslake, is still a cold month, with an average temperature ranging between min 23.9°F (-4.5°C) and max 33.6°F (0.9°C). During the transition into December, Grayslake observes a decrease in the average high-temperature, falling from a frosty 45.1°F (7.3°C) in November to a cold 33.6°F (0.9°C). Weather in December »
Updated: Aug 20, 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 part of the year is the coldest?
January brings the lowest temperatures, with an average high of 27.5°F (-2.5°C) and an average low of 16.5°F (-8.6°C).
What are the most humid months in Grayslake?
The months with the highest humidity are January and February, with an average relative humidity of 83%.
How much does it rain?
Throughout the year, there are 142.3 rainfall days, and 21.97" (558mm) of precipitation is accumulated.
When does it snow?
Months with snowfall are January through May, October through December.
When does it snow the most?
January is the month with the most snowfall in Grayslake. Snow falls for 13.7 days and accumulates 3.58" (91mm) of snow.
How many days does it snow?
Throughout the year, there are 49.5 snowfall days, and 13.54" (344mm) of snow is accumulated.
What is the month with the least sunshine?
The month with the least sunshine is January, with an average of 3.7h of sunshine.
What is the month with the lowest UV index?
January and December, with an average maximum UV index of 1, are months with the lowest UV index.
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 rainiest month?
April is the month with the most rainfall. Rain falls for 14.8 days and accumulates 2.72" (69mm) of precipitation.
When it does not snow in Grayslake?
In Grayslake, snow does not fall in June through September.
When are the longest days?
June has the longest days of the year, with an average of 15h and 12min of daylight.
What is the warmest month?
July is the warmest month, with the temperature often reaching an average high of 79.9°F (26.6°C) and an average low of 64.4°F (18°C).
When is the highest UV index?
The months with the highest UV index are July and August, with an average maximum UV index of 6.
What month has the most sunshine?
With an average of 10.2h of sunshine, August has the most sunshine of the year.
What is the least humid month?
October is the least humid month, with an average relative humidity of 74%.
What is the driest month?
December is the month with the least rainfall. Rain falls for 8.2 days and accumulates 0.98" (25mm) of precipitation.
What is the month with the shortest days?
December has the shortest days of the year, with an average of 9h and 6min of daylight.
Average temperature
Grayslake, IL
The warmest month (with the highest average high temperature) is July (79.9°F).
The month with the lowest average high temperature is January (27.5°F).
The month with the highest average low temperature is July (64.4°F).
The coldest month (with the lowest average low temperature) is January (16.5°F).
Average pressure
Grayslake, IL
- Average pressure in January:
30.1"Hg - Average pressure in February:
30.1"Hg - Average pressure in March:
30.09"Hg - Average pressure in April:
29.96"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"Hg - Average pressure in November:
30.09"Hg - Average pressure in December:
30.09"Hg
The months with the highest atmospheric pressure are January and February (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed
Grayslake, IL
- Average wind speed in January:
10.4mph - Average wind speed in February:
10.3mph - Average wind speed in March:
9.8mph - Average wind speed in April:
9.9mph - Average wind speed in May:
8.4mph - Average wind speed in June:
7.4mph
- Average wind speed in July:
6.6mph - Average wind speed in August:
6.4mph - Average wind speed in September:
7.5mph - Average wind speed in October:
9.1mph - Average wind speed in November:
9.8mph - Average wind speed in December:
9.6mph
The windiest month (with the highest average wind speed) is January (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.4mph).
Average humidity
Grayslake, IL
The months with the highest relative humidity are January and February (83%).
The month with the lowest relative humidity is October (74%).
Average rainfall
Grayslake, IL
- Average rainfall in January:
1.14" - Average rainfall in February:
1.22" - Average rainfall in March:
1.18" - Average rainfall in April:
2.72" - Average rainfall in May:
2.44" - Average rainfall in June:
2.6"
- Average rainfall in July:
2.48" - Average rainfall in August:
2.64" - Average rainfall in September:
1.57" - Average rainfall in October:
1.89" - Average rainfall in November:
1.1" - Average rainfall in December:
0.98"
The wettest month (with the highest rainfall) is April (2.72").
The driest month (with the least rainfall) is December (0.98").
Average rainfall days
Grayslake, IL
- Average rainfall days in January:
5.4 days - Average rainfall days in February:
5 days - Average rainfall days in March:
10.1 days - Average rainfall days in April:
14.8 days - Average rainfall days in May:
17 days - Average rainfall days in June:
15.7 days
- Average rainfall days in July:
17.5 days - Average rainfall days in August:
16 days - Average rainfall days in September:
11.9 days - Average rainfall days in October:
13.2 days - Average rainfall days in November:
7.5 days - Average rainfall days in December:
8.2 days
The month with the highest number of rainy days is July (17.5 days).
The month with the least rainy days is February (5 days).
Average snowfall
Grayslake, IL
- Average snowfall in January:
3.58" - Average snowfall in February:
3.54" - Average snowfall in March:
1.22" - Average snowfall in April:
1.61" - Average snowfall in May:
0.04" - Average snowfall in June:
0"
The month with the highest snowfall is January (3.58").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days
Grayslake, IL
- Average snowfall days in January:
13.7 days - Average snowfall days in February:
10.7 days - Average snowfall days in March:
7.1 days - Average snowfall days in April:
2.5 days - Average snowfall days in May:
0.2 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:
4.4 days - Average snowfall days in December:
10.4 days
The month with the highest number of snowfall days is January (13.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight / Average sunshine
Grayslake, IL
- Average daylight in January:
9h and 3min - 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 4min - Average daylight in June:
15h and 1min
- Average daylight in July:
14h and 5min - Average daylight in August:
13h and 5min - Average daylight in September:
12h and 3min - Average daylight in October:
11h and 0min - Average daylight in November:
9h and 5min - Average daylight in December:
9h and 1min
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 4min - Average sunshine in February:
3h and 5min - Average sunshine in March:
5h and 5min - Average sunshine in April:
7h and 4min - Average sunshine in May:
8h and 3min - Average sunshine in June:
9h and 4min
- Average sunshine in July:
10h and 1min - Average sunshine in August:
10h and 1min - Average sunshine in September:
8h and 5min - Average sunshine in October:
5h and 3min - Average sunshine in November:
5h and 0min - Average sunshine in December:
4h and 0min
The month with the most sunshine is August (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days
Grayslake, IL
- Average sunshine days in January:
13.7 days - Average sunshine days in February:
12.3 days - Average sunshine days in March:
14.8 days - Average sunshine days in April:
11.6 days - Average sunshine days in May:
10.8 days - Average sunshine days in June:
11.7 days
- Average sunshine days in July:
11.1 days - Average sunshine days in August:
11.7 days - Average sunshine days in September:
15.1 days - Average sunshine days in October:
14.7 days - Average sunshine days in November:
17.1 days - Average sunshine days in December:
15.4 days
The month with the most sunshine days is November (17.1 days).
The month with the least sunshine days is May (10.8 days).
Average UV index
Grayslake, IL
The months with the highest UV index are July and August (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover
Grayslake, IL
The month with the most cloud cover is January (Cloud cover 61).
The months with the least cloud cover are July, August and September (Cloud cover 30).
Average visibility
Grayslake, IL
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
Grayslake, Illinois, USA
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