Last updated: June 18, 2025
In December, the average temperature in Sarnia, Canada hovers around 0°C (33°F). Expect chilly nights with minimums plummeting to -18°C (0°F), while daytime highs can reach up to 16°C (61°F). During this month, the region experiences 55 mm (2.2 in) of precipitation spread over approximately 10 days, contributing to a high average humidity of 86%. Bundle up and be prepared for a mix of cold and damp conditions!
In December in Sarnia, the average temperature is 0°C (33°F). Maximum temperatures can reach 16°C (61°F), while minimums can dip as low as -18°C (0°F). Be prepared for a wide range of temperatures when traveling during this time.
In Sarnia in December, the precipitation amount is 55 mm (2.2 in) spread over a duration of 10 days.
In Sarnia in December humidity is 86%. With an average temperature of 0°C (33°F), this humidity feels like a damp chill that permeates your clothes, making traveling uncomfortable and necessitating warm, layered clothing to stay dry and cozy.
In Sarnia in December, the maximum UV index is 2, which corresponds to a low exposure category. With this level of UV radiation, the time to burn is approximately 45 minutes. To learn more about the hourly UV index in Sarnia, you can visit Hourly UV Index in Sarnia.
UV Risk Categories
Weather in Sarnia varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Sarnia, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -3°C (27°F) | 60 mm (2.4 inches) | 88% | low |
| February Weather | -3°C (28°F) | 66 mm (2.6 inches) | 87% | moderate |
| March Weather | 1°C (35°F) | 63 mm (2.5 inches) | 85% | moderate |
| April Weather | 7°C (45°F) | 95 mm (3.7 inches) | 86% | very high |
| May Weather | 13°C (57°F) | 97 mm (3.8 inches) | 80% | very high |
| June Weather | 20°C (68°F) | 86 mm (3.4 inches) | 80% | very high |
| July Weather | 23°C (73°F) | 73 mm (2.9 inches) | 80% | very high |
| August Weather | 22°C (72°F) | 79 mm (3.1 inches) | 80% | very high |
| September Weather | 18°C (65°F) | 73 mm (2.9 inches) | 80% | high |
| October Weather | 12°C (54°F) | 106 mm (4.2 inches) | 84% | moderate |
| November Weather | 4°C (40°F) | 72 mm (2.8 inches) | 89% | moderate |
| December Weather | 0°C (33°F) | 55 mm (2.2 inches) | 86% | low |