January weather forecast
Lake Forest, IL

Weather in January

January, the same as December, in Lake Forest, Illinois, is another subzero cold winter month, with an average temperature fluctuating between 18.9°F (-7.3°C) and 28.6°F (-1.9°C).

Temperature

January is the coldest month, with an average high-temperature of 28.6°F (-1.9°C) and an average low-temperature of 18.9°F (-7.3°C).

Humidity

The months with the highest humidity are January and February, with an average relative humidity of 82%.

Rainfall

In Lake Forest, during January, the rain falls for 6.2 days and regularly aggregates up to 1.54" (39mm) of precipitation. Throughout the year, in Lake Forest, there are 154.1 rainfall days, and 30.24" (768mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through April, October through December. January is the month with the most snowfall. Snow falls for 11.9 days and accumulates 4.13" (105mm) of snow.

Daylight

The average length of the day in January is 9h and 31min.
On the first day of the month, sunrise is at 7:20 am and sunset at 4:29 pm. On the last day of January, in Lake Forest, sunrise is at 7:05 am and sunset at 5:04 pm CST.

Sunshine

With an average of 3.8h of sunshine, January has the least sunshine of the year in Lake Forest.

UV index

In Lake Forest, Illinois, the average daily maximum UV index in January is 2. A UV Index reading of 2, and below, represents a low threat to health from exposure to the Sun's UV rays for average individuals.
Note: In January, the average maximum UV index of 2 translate into the following recommendations:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.
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FAQ

What is the coldest month in Lake Forest?

The coldest month in Lake Forest is January, with an average high-temperature of 28.6°F (-1.9°C) and an average low-temperature of 18.9°F (-7.3°C).

What is the most humid month in Lake Forest?

The months with the highest humidity are January and February, with an average relative humidity of 82%.

What is the average humidity in January in Lake Forest?

The average relative humidity in January in Lake Forest, Illinois, is 82%.

How many days does it rain in January in Lake Forest?

In Lake Forest, during January, the rain falls for 6.2 days and regularly aggregates up to 1.54" (39mm) of precipitation.

When does it snow the most in Lake Forest?

January is the month with the most snowfall. Snow falls for 11.9 days and accumulates 4.13" (105mm) of snow.

How much does it snow in Lake Forest in January?

In Lake Forest, during January, snow falls for 11.9 days and regularly aggregates up to 4.13" (105mm) of snow.

What is the average length of the day in January in Lake Forest?

In Lake Forest, Illinois, the average day length in January is 9h and 31min.

When are sunrise and sunset in January in Lake Forest?

On the first day of January in Lake Forest, sunrise is at 7:20 am and sunset at 4:29 pm. On the last day of the month, sunrise is at 7:05 am and sunset at 5:04 pm CST.

What is the month with the least sunshine in Lake Forest?

January has the least sunshine of the year in Lake Forest, with an average of 3.8h of sunshine.

How long on average sun shines in January in Lake Forest?

In January, the average sunshine duration in Lake Forest is 3.8h.

What is the UV index intensity in January in Lake Forest?

In Lake Forest, Illinois, the average daily maximum UV index in January is 2. A UV Index of 2, and less, symbolizes a low health threat from unsafe exposure to Sun's UV rays.

Average temperature in January
Lake Forest, IL

Average temperature in January - Lake Forest, IL
  • Average high temperature in January: 28.6°F

The warmest month (with the highest average high temperature) is July (77.7°F).
The month with the lowest average high temperature is January (28.6°F).

  • Average low temperature in January: 18.9°F

The months with the highest average low temperature are July and August (66.7°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).

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Average pressure in January
Lake Forest, IL

Average pressure in January - Lake Forest, IL
  • Average pressure in January: 30.1"Hg

The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

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Average wind speed in January
Lake Forest, IL

Average wind speed in January - Lake Forest, IL
  • Average wind speed in January: 11.9mph

The windiest month (with the highest average wind speed) is January (11.9mph).
The calmest month (with the lowest average wind speed) is August (7.4mph).

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Average humidity in January
Lake Forest, IL

Average humidity in January - Lake Forest, IL
  • Average humidity in January: 82%

The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is October (73%).

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Average rainfall in January
Lake Forest, IL

Average rainfall in January - Lake Forest, IL
  • Average rainfall in January: 1.54"

The wettest months (with the highest rainfall) are May and June (3.82").
The driest month (with the least rainfall) is December (1.3").

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Average rainfall days in January
Lake Forest, IL

Average rainfall days in January - Lake Forest, IL
  • Average rainfall days in January: 6.2 days

The month with the highest number of rainy days is May (17.7 days).
The month with the least rainy days is February (5.9 days).

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Average snowfall in January
Lake Forest, IL

Average snowfall in January - Lake Forest, IL
  • Average snowfall in January: 4.13"

The month with the highest snowfall is January (4.13").
The months with the least snowfall are May, June, July, August and September (0").

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Average snowfall days in January
Lake Forest, IL

Average snowfall days in January - Lake Forest, IL
  • Average snowfall days in January: 11.9 days

The month with the highest number of snowfall days is January (11.9 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

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Average daylight in January /
Average sunshine in January
Lake Forest, IL

Average daylight in January / Average sunshine in January - Lake Forest, IL
  • Average daylight in January: 9h and 31min

The month with the longest days is June (Average daylight: 15h and 13min).
The month with the shortest days is December (Average daylight: 9h and 9min).

  • Average sunshine in January: 3.8h

The month with the most sunshine is August (Average sunshine: 10.7h).
The month with the least sunshine is January (Average sunshine: 3.8h).

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Average sunshine days in January
Lake Forest, IL

Average sunshine days in January - Lake Forest, IL
  • Average sunshine days in January: 12.8 days

The month with the most sunshine days is December (15.3 days).
The month with the least sunshine days is April (10.8 days).

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Average UV index in January
Lake Forest, IL

Average UV index in January - Lake Forest, IL
  • Average UV index in January: 2

The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).

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Average cloud cover in January
Lake Forest, IL

Average cloud cover in January - Lake Forest, IL
  • Average cloud cover in January: 61

The month with the most cloud cover is January (Cloud cover 61).
The months with the least cloud cover are July and August (Cloud cover 27).

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Average visibility in January
Lake Forest, IL

Average visibility in January - Lake Forest, IL
  • Average visibility in January: 6mi

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

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