Last updated: June 24, 2025
In Knoxville, United States, the average temperature in December hovers around -1°C (31°F), with extremes ranging from a chilly -21°C (-6°F) to a mild 16°C (61°F). Expect 80 mm (3.2 in) of precipitation across about 12 days, and prepare for a moist atmosphere with an average humidity of 88%.
In December in Knoxville, the average temperature is -1°C (31°F). Maximum temperatures can reach 16°C (61°F), while minimums can drop as low as -21°C (-6°F). Travelers should be prepared for a wide range of temperatures during this month, ensuring they pack accordingly for both chilly and milder days.
In Knoxville in December, the precipitation amount is 80 mm (3.2 in) over a span of 12 days.
In Knoxville in December, humidity is 88%. With an average temperature of -1°C (31°F), this humidity feels like a biting cold that penetrates your clothing, making outdoor exploration challenging and the air clingy, adding an extra chill that can make you feel even colder than the temperature suggests.
In Knoxville 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 Knoxville, you can visit Hourly UV Index in Knoxville.
UV Risk Categories
Weather in Knoxville varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Knoxville, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -4°C (25°F) | 67 mm (2.6 inches) | 89% | moderate |
| February Weather | -2°C (28°F) | 84 mm (3.3 inches) | 90% | moderate |
| March Weather | 1°C (35°F) | 75 mm (2.9 inches) | 89% | high |
| April Weather | 7°C (46°F) | 109 mm (4.3 inches) | 88% | very high |
| May Weather | 14°C (57°F) | 116 mm (4.6 inches) | 80% | very high |
| June Weather | 19°C (66°F) | 95 mm (3.7 inches) | 79% | very high |
| July Weather | 21°C (71°F) | 124 mm (4.9 inches) | 74% | very high |
| August Weather | 20°C (69°F) | 79 mm (3.1 inches) | 64% | very high |
| September Weather | 17°C (62°F) | 89 mm (3.5 inches) | 67% | very high |
| October Weather | 11°C (52°F) | 119 mm (4.7 inches) | 81% | high |
| November Weather | 3°C (38°F) | 78 mm (3.1 inches) | 89% | moderate |
| December Weather | -1°C (31°F) | 80 mm (3.2 inches) | 88% | low |