Last updated: June 24, 2025
In December, the average temperature in West Haven-Sylvan, United States hovers around 5°C (41°F). Minimum temperatures can drop to a chilly -5°C (24°F), while highs reach a pleasant 16°C (60°F). Expect 183 mm (7.2 in) of precipitation over approximately 19 days, with humidity levels averaging a notable 87%.
In December in West Haven-Sylvan, the average temperature is 5°C (41°F). The maximum can reach 16°C (60°F), while the minimum can drop as low as -5°C (24°F). It's advisable to pack layers and prepare for varying conditions when traveling during this time.
In West Haven-Sylvan in December, the total precipitation amount is 183 mm (7.2 in) over a span of 19 days.
In West Haven-Sylvan in December humidity is 87%. With an average temperature of 5°C (41°F), this humidity feels like a heavy, damp blanket enveloping you, making every step seem laborious and the chill more biting, which can be quite challenging for traveling.
In West Haven-Sylvan 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 West Haven-Sylvan, you can visit Hourly UV Index in West Haven-Sylvan.
UV Risk Categories
Weather in West Haven-Sylvan varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in West Haven-Sylvan, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 5°C (42°F) | 163 mm (6.4 inches) | 85% | low |
| February Weather | 5°C (41°F) | 172 mm (6.8 inches) | 84% | moderate |
| March Weather | 8°C (46°F) | 135 mm (5.3 inches) | 85% | moderate |
| April Weather | 11°C (51°F) | 117 mm (4.6 inches) | 83% | high |
| May Weather | 14°C (58°F) | 58 mm (2.3 inches) | 83% | very high |
| June Weather | 18°C (64°F) | 46 mm (1.8 inches) | 83% | very high |
| July Weather | 21°C (69°F) | 6 mm (0.2 inches) | 82% | very high |
| August Weather | 21°C (70°F) | 8 mm (0.3 inches) | 74% | very high |
| September Weather | 18°C (64°F) | 62 mm (2.4 inches) | 71% | high |
| October Weather | 12°C (53°F) | 105 mm (4.1 inches) | 81% | moderate |
| November Weather | 8°C (47°F) | 155 mm (6.1 inches) | 87% | moderate |
| December Weather | 5°C (41°F) | 183 mm (7.2 inches) | 87% | low |