Last updated: June 24, 2025
In Sussex, United States, the average temperature in December hovers around 1°C (34°F). Expect a chilly range, with minimums dropping to -18°C (-1°F) and maximums reaching up to 17°C (62°F). During this period, the region sees 103 mm (4.1 in) of precipitation spread over 11 days, contributing to an average humidity level of 80%. Prepare accordingly for a wet and crisp month!
In December in Sussex, the average temperature is 1°C (34°F). Maximums can reach 17°C (62°F), while minimums can be as low as -18°C (-1°F). Travelers should be prepared for a wide range of temperatures, from chilly conditions to relatively mild days.
In Sussex in December, the precipitation amount is 103 mm (4.1 in) spread over 11 days.
In Sussex in December, humidity is 80%. With an average temperature of 1°C (34°F), this humidity feels like a damp chill that seeps through your layers, making outdoor activities uncomfortable and potentially discouraging for travelers.
In Sussex 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 Sussex, you can visit Hourly UV Index in Sussex.
UV Risk Categories
Weather in Sussex varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Sussex, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -1°C (30°F) | 71 mm (2.8 inches) | 84% | moderate |
| February Weather | 0°C (33°F) | 98 mm (3.8 inches) | 82% | moderate |
| March Weather | 3°C (39°F) | 92 mm (3.6 inches) | 81% | high |
| April Weather | 10°C (49°F) | 114 mm (4.5 inches) | 78% | very high |
| May Weather | 15°C (60°F) | 129 mm (5.1 inches) | 69% | very high |
| June Weather | 20°C (69°F) | 97 mm (3.8 inches) | 69% | very high |
| July Weather | 24°C (75°F) | 135 mm (5.3 inches) | 62% | very high |
| August Weather | 22°C (73°F) | 130 mm (5.1 inches) | 65% | very high |
| September Weather | 19°C (66°F) | 107 mm (4.2 inches) | 68% | very high |
| October Weather | 13°C (56°F) | 139 mm (5.5 inches) | 74% | high |
| November Weather | 5°C (42°F) | 88 mm (3.5 inches) | 82% | moderate |
| December Weather | 1°C (34°F) | 103 mm (4.1 inches) | 80% | low |