Last updated: June 24, 2025
In Sidney, United States, the average temperature in December hovers around 1°C (35°F), with extremes ranging from a chilly -21°C (-5°F) to a warm 25°C (76°F). This month typically sees 14 mm (0.6 in) of precipitation spread over 3 days, and the average humidity remains relatively high at 77%. Whether you're bundling up for the cold or enjoying the occasional warmth, be prepared for a diverse range of weather conditions!
In December in Sidney, the average temperature is 1°C (35°F), with maximums that can reach 25°C (76°F) and minimums that can drop as low as -21°C (-5°F). It's important to prepare for a wide range of temperatures when traveling during this time.
In Sidney in December, the precipitation amount is 14 mm (0.6 in) accumulated over the course of 3 days.
In Sidney in December, humidity is 77%. With an average temperature of 1°C (35°F), this humidity feels like a heavy fog, making travel feel damp and chilly, as the cold air clings to your skin and every breath is filled with moisture.
In Sidney in December, 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 Sidney, you can check the information here.
UV Risk Categories
Weather in Sidney varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Sidney, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 0°C (32°F) | 12 mm (0.5 inches) | 72% | moderate |
| February Weather | -1°C (30°F) | 18 mm (0.7 inches) | 76% | moderate |
| March Weather | 5°C (42°F) | 63 mm (2.5 inches) | 61% | high |
| April Weather | 9°C (48°F) | 58 mm (2.3 inches) | 60% | very high |
| May Weather | 14°C (57°F) | 116 mm (4.6 inches) | 74% | very high |
| June Weather | 22°C (71°F) | 51 mm (2.0 inches) | 82% | extreme |
| July Weather | 24°C (76°F) | 48 mm (1.9 inches) | 82% | extreme |
| August Weather | 23°C (73°F) | 31 mm (1.2 inches) | 84% | very high |
| September Weather | 19°C (67°F) | 26 mm (1.0 inches) | 75% | very high |
| October Weather | 9°C (49°F) | 31 mm (1.2 inches) | 73% | high |
| November Weather | 6°C (42°F) | 21 mm (0.8 inches) | 74% | moderate |
| December Weather | 1°C (35°F) | 14 mm (0.6 inches) | 77% | moderate |