Last updated: June 24, 2025
In December, the average temperature in New Haven, United States hovers around 1°C (35°F). Expect a chill in the air, with minimums plunging to -21°C (-6°F) and occasional highs reaching up to 17°C (63°F). During this month, you'll likely encounter 61 mm (2.4 in) of precipitation over about 9 days, accompanied by a damp average humidity of 86%.
In December in New Haven, the average temperature is 1°C (35°F). The maximum can reach 17°C (63°F), while the minimum can drop as low as -21°C (-6°F). Be prepared for a wide range of temperatures and pack accordingly when traveling to New Haven in December.
In New Haven in December, the precipitation amount is 61 mm (2.4 in) spread over 9 days.
In New Haven in December, humidity is 86%. With an average temperature of 1°C (35°F), this humidity feels like a biting chill that wraps around you, making outdoor exploration uncomfortable and requiring extra layers to stay warm while navigating the damp air.
In New Haven 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 New Haven, you can visit Hourly UV Index in New Haven.
UV Risk Categories
Weather in New Haven varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in New Haven, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -2°C (29°F) | 74 mm (2.9 inches) | 85% | moderate |
| February Weather | -1°C (31°F) | 80 mm (3.2 inches) | 85% | moderate |
| March Weather | 5°C (41°F) | 102 mm (4.0 inches) | 86% | high |
| April Weather | 10°C (50°F) | 92 mm (3.6 inches) | 87% | very high |
| May Weather | 17°C (63°F) | 127 mm (5.0 inches) | 81% | very high |
| June Weather | 22°C (72°F) | 121 mm (4.8 inches) | 82% | very high |
| July Weather | 24°C (76°F) | 104 mm (4.1 inches) | 81% | very high |
| August Weather | 23°C (74°F) | 96 mm (3.8 inches) | 79% | very high |
| September Weather | 20°C (68°F) | 65 mm (2.5 inches) | 78% | very high |
| October Weather | 14°C (57°F) | 101 mm (4.0 inches) | 81% | high |
| November Weather | 5°C (41°F) | 82 mm (3.2 inches) | 89% | moderate |
| December Weather | 1°C (35°F) | 61 mm (2.4 inches) | 86% | low |