Last updated: June 24, 2025
In Ashton-Sandy Spring, United States, the average temperature in December is a cool 4°C (40°F). Be prepared for a range of temperatures, with a minimum of -11°C (12°F) and a maximum of 19°C (67°F). During this time, expect approximately 95 mm (3.7 in) of precipitation spread over 9 days, contributing to an average humidity of 84%.
In December in Ashton-Sandy Spring, the average temperature is 4°C (40°F). The maximum can reach 19°C (67°F) and the minimum can be as low as -11°C (12°F). Be prepared for a wide temperature range if you're planning to travel during this time.
In Ashton-Sandy Spring in December, the precipitation amount is 95 mm (3.7 in) over the course of 9 days.
In Ashton-Sandy Spring in December, humidity is 84%. 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 requiring extra layers to stay warm and dry while traveling.
In Ashton-Sandy Spring 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 Ashton-Sandy Spring, you can check the information here.
UV Risk Categories
Weather in Ashton-Sandy Spring varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Ashton-Sandy Spring, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 2°C (36°F) | 60 mm (2.4 inches) | 84% | moderate |
| February Weather | 4°C (40°F) | 99 mm (3.9 inches) | 83% | moderate |
| March Weather | 7°C (45°F) | 89 mm (3.5 inches) | 83% | high |
| April Weather | 13°C (56°F) | 94 mm (3.7 inches) | 81% | very high |
| May Weather | 18°C (65°F) | 139 mm (5.5 inches) | 78% | very high |
| June Weather | 23°C (74°F) | 133 mm (5.2 inches) | 79% | very high |
| July Weather | 26°C (80°F) | 168 mm (6.6 inches) | 74% | very high |
| August Weather | 25°C (77°F) | 148 mm (5.8 inches) | 72% | very high |
| September Weather | 21°C (71°F) | 105 mm (4.1 inches) | 75% | very high |
| October Weather | 16°C (61°F) | 106 mm (4.2 inches) | 81% | high |
| November Weather | 8°C (47°F) | 84 mm (3.3 inches) | 85% | moderate |
| December Weather | 4°C (40°F) | 95 mm (3.7 inches) | 84% | moderate |