Last updated: August 27, 2025
In December, the average temperature in Castletown, United Kingdom hovers around 6°C (43°F), with a minimum dipping to as low as -3°C (27°F) and a maximum reaching up to 13°C (56°F). This month sees approximately 71 mm (2.8 in) of precipitation spread over 17 days. Travelers can expect 80% humidity, making for a cool and damp atmosphere.
In December in Castletown, the average temperature is 6°C (43°F), with maximums reaching up to 13°C (56°F) and minimums dropping as low as -3°C (27°F). Be sure to pack layers and prepare for chilly evenings if you're planning to visit during this time!
In Castletown in December, the total precipitation amount is 71 mm (2.8 in) over the course of 17 days.
In Castletown in December humidity is 80%. With an average temperature of 6°C (43°F), this humidity feels like a chilly, damp embrace that can make outdoor exploration quite uncomfortable, often leaving travelers feeling clammy and cold despite the relatively mild temperature.
In Castletown 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 Castletown.
UV Risk Categories
Weather in Castletown varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Castletown, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 5°C (42°F) | 57 mm (2.2 inches) | 82% | low |
| February Weather | 5°C (42°F) | 62 mm (2.5 inches) | 81% | low |
| March Weather | 6°C (43°F) | 72 mm (2.8 inches) | 81% | moderate |
| April Weather | 7°C (45°F) | 55 mm (2.2 inches) | 81% | moderate |
| May Weather | 10°C (50°F) | 67 mm (2.6 inches) | 83% | moderate |
| June Weather | 13°C (55°F) | 70 mm (2.8 inches) | 84% | high |
| July Weather | 14°C (58°F) | 74 mm (2.9 inches) | 87% | high |
| August Weather | 14°C (58°F) | 79 mm (3.1 inches) | 86% | high |
| September Weather | 13°C (55°F) | 109 mm (4.3 inches) | 88% | moderate |
| October Weather | 10°C (51°F) | 112 mm (4.4 inches) | 87% | moderate |
| November Weather | 8°C (46°F) | 92 mm (3.6 inches) | 87% | low |
| December Weather | 6°C (43°F) | 71 mm (2.8 inches) | 80% | low |