Last updated: June 18, 2025
In December, the average temperature in St. Thomas, Canada hovers around 1°C (34°F), with a minimum dipping to a brisk -16°C (4°F) and a maximum reaching up to 13°C (56°F). Expect about 77 mm (3.0 in) of precipitation over 13 days, contributing to a notably high average humidity of 87%.
In December in St. Thomas, the average temperature is 1°C (34°F), with maximums reaching up to 13°C (56°F) and minimums plunging as low as -16°C (4°F). Be prepared for a wide range of weather if you plan to travel during this month!
In St. Thomas in December, the precipitation amount is 77 mm (3.0 in) spread over a total of 13 days.
In St. Thomas in December humidity is 87%. With an average temperature of 1°C (34°F), this humidity feels like a chilling blanket enveloping you, making every step outside feel heavy and damp, and leaving you longing for warmth and comfort while traveling.
In St. Thomas 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 St. Thomas, you can visit Hourly UV Index in St. Thomas.
UV Risk Categories
Weather in St. Thomas varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in St. Thomas, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -3°C (27°F) | 76 mm (3.0 inches) | 90% | moderate |
| February Weather | -3°C (27°F) | 79 mm (3.1 inches) | 90% | moderate |
| March Weather | 1°C (34°F) | 81 mm (3.2 inches) | 87% | moderate |
| April Weather | 6°C (43°F) | 106 mm (4.2 inches) | 87% | very high |
| May Weather | 13°C (55°F) | 99 mm (3.9 inches) | 82% | very high |
| June Weather | 19°C (66°F) | 93 mm (3.7 inches) | 81% | very high |
| July Weather | 22°C (72°F) | 91 mm (3.6 inches) | 79% | very high |
| August Weather | 22°C (71°F) | 96 mm (3.8 inches) | 80% | very high |
| September Weather | 18°C (65°F) | 82 mm (3.2 inches) | 81% | very high |
| October Weather | 12°C (55°F) | 123 mm (4.9 inches) | 84% | high |
| November Weather | 5°C (41°F) | 94 mm (3.7 inches) | 88% | moderate |
| December Weather | 1°C (34°F) | 77 mm (3.0 inches) | 87% | low |