Prince William Forest Park experiences all four seasons.

Spring and fall are generally comfortable with precipitation possible.

Summers can be hot and humid with average temperatures in the high 80s and with sudden thunderstorms possible.  July and August are the hottest months.

Winters can be cold with average temperatures in the winter of 41 degrees with variable precipitation.  The main park roads can close due to snowy conditions, though cross-country skiing and snow-shoeing are permitted.  Winter visitors must prepare for a variety of conditions and contact the park visitor center (703-221-7181) for information on current weather conditions. 

A hat, comfortable clothing and sturdy walking shoes or boots are necessary for anyone planning to hike. Hikers must always carry plenty of water. One gallon per person per day is recommended.