Last updated: August 27, 2025
In December, the average temperature in Thornhill, United Kingdom hovers around 4°C (40°F), with minimums dropping to -7°C (19°F) and maximums reaching up to 12°C (53°F). Expect 122 mm (4.8 in) of precipitation spread over 17 days, contributing to an average humidity of 89%. Prepare for a chilly and damp month!
In December in Thornhill, the average temperature is 4°C (40°F). Maximum temperatures can reach 12°C (53°F), while minimums can drop as low as -7°C (19°F). Travelers should be prepared for chilly weather and pack accordingly.
In Thornhill in December, the precipitation amount is 122 mm (4.8 in) spread over the course of 17 days.
In Thornhill in December humidity is 89%. With an average temperature of 4°C (40°F), this humidity feels like a chilling blanket enveloping you, making travel uncomfortable and damp, as the cold penetrates through your clothes and the air feels heavy and clinging.
In Thornhill in December, the maximum UV index is 1, which corresponds to a low Exposure Category. This means you have a time to burn of 45 minutes. For more details, you can check the Hourly UV Index in Thornhill.
UV Risk Categories
Weather in Thornhill varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Thornhill, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 3°C (38°F) | 86 mm (3.4 inches) | 90% | low |
| February Weather | 4°C (39°F) | 161 mm (6.3 inches) | 88% | low |
| March Weather | 5°C (41°F) | 116 mm (4.6 inches) | 86% | moderate |
| April Weather | 7°C (45°F) | 47 mm (1.9 inches) | 85% | moderate |
| May Weather | 10°C (50°F) | 75 mm (2.9 inches) | 80% | high |
| June Weather | 13°C (56°F) | 112 mm (4.4 inches) | 83% | very high |
| July Weather | 15°C (59°F) | 103 mm (4.0 inches) | 82% | very high |
| August Weather | 14°C (57°F) | 144 mm (5.7 inches) | 82% | high |
| September Weather | 12°C (54°F) | 101 mm (4.0 inches) | 88% | moderate |
| October Weather | 9°C (48°F) | 142 mm (5.6 inches) | 90% | moderate |
| November Weather | 6°C (43°F) | 121 mm (4.8 inches) | 92% | low |
| December Weather | 4°C (40°F) | 122 mm (4.8 inches) | 89% | low |