Last updated: June 24, 2025
In December, the average temperature in Mount Vernon, United States is a cool 13°C (55°F). Temperatures can vary significantly, with a minimum of -3°C (27°F) and a maximum soaring to 27°C (81°F). Visitors should be prepared for some rain, as the region experiences approximately 130 mm (5.1 in) of precipitation over 12 days. With an average humidity level of 87%, the air feels quite damp, making it an ideal time for cozy indoor activities or exploring the vibrant local culture.
In December in Mount Vernon, the average temperature is 13°C (55°F), with maximums reaching 27°C (81°F) and minimums dropping as low as -3°C (27°F). This makes it an ideal time for travelers to experience a range of weather conditions, allowing for both outdoor activities and cozy indoor experiences.
In Mount Vernon in December, the precipitation amount is 130 mm (5.1 in) over a span of 12 days.
In Mount Vernon in December, humidity is 87%. With an average temperature of 13°C (55°F), this humidity feels like a heavy blanket wrapping around you, making travel sluggish and slightly uncomfortable, as each step seems to cling to the damp air.
In Mount Vernon in December, the maximum UV index reaches 4, which corresponds to a moderate Exposure Category. With a time to burn of 30 minutes, it’s important to take precautions to protect your skin. You can find more details in the Hourly UV Index in Mount Vernon for better planning.
UV Risk Categories
Weather in Mount Vernon varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Mount Vernon, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 11°C (52°F) | 102 mm (4.0 inches) | 82% | moderate |
| February Weather | 14°C (58°F) | 98 mm (3.9 inches) | 80% | very high |
| March Weather | 17°C (63°F) | 108 mm (4.2 inches) | 80% | very high |
| April Weather | 20°C (67°F) | 120 mm (4.7 inches) | 78% | extreme |
| May Weather | 24°C (76°F) | 141 mm (5.6 inches) | 73% | extreme |
| June Weather | 27°C (80°F) | 210 mm (8.3 inches) | 71% | extreme |
| July Weather | 28°C (82°F) | 149 mm (5.9 inches) | 79% | extreme |
| August Weather | 27°C (82°F) | 160 mm (6.3 inches) | 78% | extreme |
| September Weather | 26°C (79°F) | 132 mm (5.2 inches) | 80% | very high |
| October Weather | 22°C (72°F) | 119 mm (4.7 inches) | 76% | very high |
| November Weather | 15°C (59°F) | 65 mm (2.6 inches) | 83% | high |
| December Weather | 13°C (55°F) | 130 mm (5.1 inches) | 87% | moderate |