Last updated: June 24, 2025
In Castlewood, United States, the average temperature in December hovers around 4°C (40°F), with extremes ranging from a chilling -21°C (-6°F) to a mild 19°C (67°F). Expect 122 mm (4.8 in) of precipitation across 11 days, contributing to a high average humidity of 86%. Whether wrapped up warm or dodging the rain, be prepared for a dynamic month of weather!
In December in Castlewood, the average temperature is 4°C (40°F), with a maximum that can reach 19°C (67°F) and a minimum that can drop as low as -21°C (-6°F). It's advisable to pack layers and prepare for a wide range of temperatures when traveling during this month.
In Castlewood in December, the total precipitation amount is 122 mm (4.8 in) over a span of 11 days.
In Castlewood in December humidity is 86%. With an average temperature of 4°C (40°F), this humidity feels like a damp chill that seeps into your bones, making outdoor activities uncomfortable and travel cumbersome as you navigate through a thick, heavy air that clings to your skin.
In Castlewood 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 Castlewood, you can check the information here.
UV Risk Categories
Weather in Castlewood varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Castlewood, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 2°C (36°F) | 91 mm (3.6 inches) | 87% | moderate |
| February Weather | 5°C (42°F) | 164 mm (6.4 inches) | 87% | high |
| March Weather | 8°C (47°F) | 126 mm (5.0 inches) | 86% | very high |
| April Weather | 12°C (54°F) | 155 mm (6.1 inches) | 84% | very high |
| May Weather | 18°C (64°F) | 129 mm (5.1 inches) | 83% | extreme |
| June Weather | 21°C (69°F) | 149 mm (5.8 inches) | 83% | extreme |
| July Weather | 23°C (73°F) | 114 mm (4.5 inches) | 79% | extreme |
| August Weather | 22°C (71°F) | 131 mm (5.1 inches) | 66% | very high |
| September Weather | 20°C (68°F) | 118 mm (4.6 inches) | 68% | very high |
| October Weather | 14°C (58°F) | 127 mm (5.0 inches) | 78% | high |
| November Weather | 7°C (44°F) | 77 mm (3.0 inches) | 89% | moderate |
| December Weather | 4°C (40°F) | 122 mm (4.8 inches) | 86% | moderate |