Last updated: June 24, 2025
In Sullivan, United States, the average temperature in January hovers around 0°C (33°F). Expect a chilly range with minimums dipping to -21°C (-6°F) and maximums reaching a mild 19°C (67°F). This month also brings about 90 mm (3.6 in) of precipitation over 9 days, paired with an average humidity of 84%. Stay prepared for a moist and brisk experience!
In January in Sullivan, the average temperature is 0°C (33°F). The maximum can reach 19°C (67°F), and the minimum can be as low as -21°C (-6°F). Be prepared for a wide range of temperatures if you plan to travel during this time.
In Sullivan in January, the precipitation amount is 90 mm (3.6 in) spread over the course of 9 days.
In Sullivan in January humidity is 84%. With average temperature 0°C (33°F), this humidity feels like a damp chill that seeps into your bones, making outdoor adventures less enjoyable and travel plans challenging.
In Sullivan in January, the maximum UV index is 3, which corresponds to a moderate Exposure Category. The time to burn is approximately 30 minutes. For more details on the hourly UV index in Sullivan, you can check the information here.
UV Risk Categories
Weather in Sullivan varies notably across the year, with each month offering distinct climate conditions. This page compares January’s weather to other months in Sullivan, focusing on differences in temperature, rainfall, humidity, and UV levels.
Temperature | Precipitation | Humidity | UV | |
---|---|---|---|---|
January Weather | 0°C (33°F) | 90 mm (3.6 inches) | 84% | moderate |
February Weather | 2°C (36°F) | 103 mm (4.1 inches) | 82% | moderate |
March Weather | 8°C (46°F) | 127 mm (5.0 inches) | 84% | high |
April Weather | 13°C (55°F) | 122 mm (4.8 inches) | 83% | very high |
May Weather | 19°C (67°F) | 130 mm (5.1 inches) | 80% | very high |
June Weather | 24°C (76°F) | 113 mm (4.4 inches) | 83% | extreme |
July Weather | 26°C (79°F) | 111 mm (4.4 inches) | 82% | very high |
August Weather | 24°C (76°F) | 95 mm (3.8 inches) | 82% | very high |
September Weather | 22°C (72°F) | 68 mm (2.7 inches) | 79% | very high |
October Weather | 15°C (60°F) | 95 mm (3.7 inches) | 79% | high |
November Weather | 6°C (44°F) | 104 mm (4.1 inches) | 88% | moderate |
December Weather | 3°C (39°F) | 94 mm (3.7 inches) | 87% | moderate |