January Weather in Lake Forest, United States

Last updated: June 24, 2025

In January, the average temperature in Lake Forest, United States hovers around 13°C (56°F). Temperatures can fluctuate significantly, with a minimum of 3°C (38°F) and a maximum of 31°C (88°F). Expect about 71 mm (2.8 in) of precipitation spread over 5 days, contributing to an average humidity of 74%. Prepare for a mix of mild warmth and occasional rain!

January Temperature in Lake Forest

In January in Lake Forest, the average temperature is 13°C (56°F). The maximum can reach 31°C (88°F), while the minimum can be as low as 3°C (38°F). It's advisable to pack layers to accommodate for the varying temperatures during your travels.

January Weather in Lake Forest: Daily Temperature Highs, Lows, and Averages

The chart illustrates January temperature patterns in Lake Forest, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Lake Forest, January typically has an average temperature of 13°C (56°F), with highs reaching up to 31°C (88°F) and lows dropping to around 3°C (38°F).

Data source: Temperature data for Lake Forest generated using information from the Copernicus Climate Change Service.

January Precipitation in Lake Forest

In Lake Forest in January, the precipitation amount is 71 mm (2.8 in) over the course of 5 days.

January Precipitation Trends in Lake Forest

The chart displays monthly precipitation patterns in Lake Forest, with values for each month alongside January’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how January’s conditions compare to those of other months. In Lake Forest, January typically receives around 71 mm (2.8 inches) of precipitation spread over approximately 5 days.

Data source: Precipitation data for January generated using information from the Copernicus Climate Change Service.

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

January Humidity in Lake Forest

In Lake Forest in January humidity is 74%. With an average temperature of 13°C (56°F), this humidity feels like a damp chill that can make outdoor activities uncomfortable, especially for travelers unaccustomed to such conditions.

January Average Humidity in Lake Forest

This chart illustrates the average monthly humidity levels in Lake Forest, with January’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In January, average humidity in Lake Forest is approximately 74%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for January generated using information from the Copernicus Climate Change Service.

January UV Index in Lake Forest

In Lake Forest in January, the maximum UV index reaches 4, which corresponds to a moderate Exposure Category. With a time to burn of 30 minutes, it’s important to take precautions to protect your skin. You can find more details in the Hourly UV Index in Lake Forest for better planning.

Maximum UV Index Levels in Lake Forest for January

The chart shows the monthly maximum UV Index (UVI) for Lake Forest in January, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In January, the maximum UV index in Lake Forest typically reaches 4, which falls under the moderate exposure category.

Data source: Lake Forest January UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

How January Weather in Lake Forest Compares to Other Months

Weather in Lake Forest varies notably across the year, with each month offering distinct climate conditions. This page compares January’s weather to other months in Lake Forest, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Lake Forest, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	13°C (56°F)	71 mm (2.8 inches)	74%	moderate
February Weather	13°C (56°F)	60 mm (2.3 inches)	79%	high
March Weather	14°C (58°F)	68 mm (2.7 inches)	75%	very high
April Weather	17°C (62°F)	27 mm (1.1 inches)	70%	very high
May Weather	17°C (64°F)	13 mm (0.5 inches)	70%	extreme
June Weather	20°C (68°F)	1 mm (0.0 inches)	72%	extreme
July Weather	23°C (73°F)	2 mm (0.1 inches)	73%	extreme
August Weather	23°C (74°F)	2 mm (0.1 inches)	69%	very high
September Weather	22°C (72°F)	3 mm (0.1 inches)	68%	very high
October Weather	20°C (69°F)	10 mm (0.4 inches)	67%	high
November Weather	17°C (62°F)	25 mm (1.0 inches)	68%	moderate
December Weather	13°C (56°F)	74 mm (2.9 inches)	71%	moderate