Last updated: June 18, 2025
In Westmount, Canada, the average temperature in December hovers around -5°C (24°F). Be prepared for chilly extremes, as temperatures can dip to a frigid -26°C (-15°F), while the mildest days reach up to 14°C (57°F). Expect about 88 mm (3.5 in) of precipitation spread across 12 days, contributing to an average humidity of a damp 89%. Bundle up and enjoy the wintery charm!
In December in Westmount, the average temperature is -5°C (24°F). Maximums can reach 14°C (57°F), while minimums can drop as low as -26°C (-15°F). Be prepared for a wide range of temperatures if you plan to travel during this time.
In Westmount in December, the precipitation amount is 88 mm (3.5 in) over a span of 12 days.
In Westmount in December humidity is 89%. With an average temperature of -5°C (24°F), this humidity feels like an uncomfortable chill enveloping you, making outdoor activities less enjoyable and requiring extra layers to stay warm while battling the dampness in the air.
In Westmount 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 Westmount, you can visit Hourly UV Index in Westmount.
UV Risk Categories
Weather in Westmount varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Westmount, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -8°C (17°F) | 84 mm (3.3 inches) | 93% | low |
| February Weather | -7°C (20°F) | 82 mm (3.2 inches) | 92% | moderate |
| March Weather | -2°C (29°F) | 84 mm (3.3 inches) | 86% | moderate |
| April Weather | 6°C (43°F) | 121 mm (4.7 inches) | 85% | high |
| May Weather | 14°C (57°F) | 97 mm (3.8 inches) | 80% | very high |
| June Weather | 19°C (67°F) | 103 mm (4.1 inches) | 74% | very high |
| July Weather | 22°C (72°F) | 103 mm (4.1 inches) | 76% | very high |
| August Weather | 21°C (70°F) | 109 mm (4.3 inches) | 75% | very high |
| September Weather | 16°C (62°F) | 73 mm (2.9 inches) | 78% | high |
| October Weather | 10°C (50°F) | 139 mm (5.5 inches) | 86% | moderate |
| November Weather | 2°C (35°F) | 118 mm (4.6 inches) | 88% | moderate |
| December Weather | -5°C (24°F) | 88 mm (3.5 inches) | 89% | low |