Upper Marlboro Weather in December

The climate in Upper Marlboro during December can be summarized as cool and a little damp.

December is in the winter in Upper Marlboro and is typically the 3rd coldest month of the year. Daytime maximum temperatures average around a cold 8°C (46°F), whilst at night -2°C (28°F) is normal.

On average December is the 5th driest month of the year in Upper Marlboro with around 85mm 3.4 inches of rain making it a a little damp time to visit. This rainfall is typically spread over 9 days, although this may vary considerably.

On the flip side this corresponds to an average of 5.2 hours of sunshine per day.

The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in Upper Marlboro in December 2025.