Last updated: June 24, 2025
In December, the average temperature in Lake Forest, United States hovers around 13°C (56°F), making it a pleasant time to explore. Expect temperatures to range from a cool 4°C (39°F) to a warm 28°C (82°F). During this month, you may encounter 74 mm (2.9 in) of precipitation spread over about 5 days, contributing to an average humidity of 71%. Be prepared for a mix of sunshine and occasional showers!
In December in Lake Forest, the average temperature is 13°C (56°F). The maximum can reach 28°C (82°F), while the minimum can drop as low as 4°C (39°F). This makes Lake Forest an ideal destination for travelers seeking mild weather with a pleasant range of temperatures.
In Lake Forest in December, the total precipitation amount is 74 mm (2.9 in) over a span of 5 days.
In Lake Forest in December humidity is 71%. With an average temperature of 13°C (56°F), this humidity feels like a damp embrace that can make exploring the area feel a bit stifling and requires light, breathable clothing to remain comfortable while traveling.
In Lake Forest in December, 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.
UV Risk Categories
Weather in Lake Forest varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Lake Forest, focusing on differences in temperature, rainfall, humidity, and UV levels.
| 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 |