Last updated: June 24, 2025
In December, the average temperature in Newcastle, United States hovers around 10°C (50°F). Expect a range with lows dipping to -7°C (20°F) and highs reaching up to 32°C (89°F). You'll encounter approximately 41 mm (1.6 in) of precipitation spread over about 4 days, contributing to a notably high average humidity of 85%.
In December in Newcastle, the average temperature is 10°C (50°F). The maximum can reach 32°C (89°F), and the minimum can be as low as -7°C (20°F). This wide range of temperatures makes it essential for travelers to pack both warm and light clothing to enjoy their visit comfortably.
In Newcastle in December, the precipitation amount is 41 mm (1.6 in) over the course of 4 days.
In Newcastle in December, humidity is 85%. With an average temperature of 10°C (50°F), this humidity feels like a heavy, damp blanket surrounding you, making travel feel sluggish and uncomfortable as you navigate through the thick, moist air.
In Newcastle 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 Newcastle for better planning.
UV Risk Categories
Weather in Newcastle varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Newcastle, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 7°C (45°F) | 37 mm (1.5 inches) | 77% | moderate |
| February Weather | 8°C (47°F) | 44 mm (1.7 inches) | 76% | high |
| March Weather | 15°C (59°F) | 71 mm (2.8 inches) | 74% | very high |
| April Weather | 18°C (65°F) | 63 mm (2.5 inches) | 75% | very high |
| May Weather | 24°C (75°F) | 99 mm (3.9 inches) | 80% | extreme |
| June Weather | 28°C (83°F) | 57 mm (2.2 inches) | 80% | extreme |
| July Weather | 30°C (87°F) | 23 mm (0.9 inches) | 75% | extreme |
| August Weather | 30°C (86°F) | 48 mm (1.9 inches) | 67% | extreme |
| September Weather | 26°C (79°F) | 94 mm (3.7 inches) | 64% | very high |
| October Weather | 19°C (67°F) | 78 mm (3.1 inches) | 70% | very high |
| November Weather | 13°C (55°F) | 33 mm (1.3 inches) | 82% | high |
| December Weather | 10°C (50°F) | 41 mm (1.6 inches) | 85% | moderate |