Last updated: June 24, 2025
In December, the average temperature in Willow Grove, United States hovers around 4°C (39°F). Expect chilly nights with minimum temperatures dipping to -12°C (12°F), while daytime can reach a cozy 19°C (66°F). Throughout the month, expect approximately 105 mm (4.1 in) of precipitation over about 10 days, contributing to an average humidity level of 85%—making it feel quite fresh!
In December in Willow Grove, the average temperature is 4°C (39°F), with maximums reaching up to 19°C (66°F) and minimums dropping as low as -12°C (12°F). It's advisable to dress in layers and prepare for chilly conditions if you plan to travel during this time.
In Willow Grove in December, the precipitation amount is 105 mm (4.1 in) over the course of 10 days.
In Willow Grove in December, humidity is 85%. With an average temperature of 4°C (39°F), this humidity feels like a damp chill that seeps into your bones, making traveling uncomfortable and requiring extra layers to ward off the cold and moisture.
In Willow Grove 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 Willow Grove, you can visit Hourly UV Index in Willow Grove.
UV Risk Categories
Weather in Willow Grove varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Willow Grove, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 1°C (35°F) | 66 mm (2.6 inches) | 87% | moderate |
| February Weather | 3°C (38°F) | 108 mm (4.2 inches) | 85% | moderate |
| March Weather | 6°C (43°F) | 110 mm (4.3 inches) | 85% | high |
| April Weather | 12°C (53°F) | 106 mm (4.2 inches) | 83% | very high |
| May Weather | 17°C (63°F) | 138 mm (5.4 inches) | 75% | very high |
| June Weather | 22°C (72°F) | 103 mm (4.0 inches) | 73% | very high |
| July Weather | 25°C (78°F) | 145 mm (5.7 inches) | 65% | very high |
| August Weather | 24°C (76°F) | 146 mm (5.8 inches) | 62% | very high |
| September Weather | 21°C (70°F) | 91 mm (3.6 inches) | 66% | very high |
| October Weather | 16°C (60°F) | 112 mm (4.4 inches) | 79% | high |
| November Weather | 8°C (46°F) | 83 mm (3.3 inches) | 87% | moderate |
| December Weather | 4°C (39°F) | 105 mm (4.1 inches) | 85% | low |