Weather Report at Valley Forge 1775-1782
The winter at Valley Forge was a rough one. But, a winter encampment at Morristown, New Jersey was worse. The Valley Forge Encampment was difficult because the soldiers lacked proper clothing and proper meals. There were seven winters during the Revolutionary War.
The winters could be rated on the following scale: severe, moderate and mild.
There are two excellent resources providing an account of the weather situation in the Philadelphia region during the winter of 1777-1778. One is that of Thomas Coombe, from his residence "two miles west of Philadelphia" (which would be in the city today) and that of Rev. Henry Melchior Muhlenberg, from Providence (now Trappe, approximately 10-12 miles from Valley Forge), near the Perkiomen River in Montgomery County.
The Encampment saw basically two periods of severe cold. The end of December with a low of 6 Degrees and the end of March with a low of 8 Degrees. The low in January reached 12 Degrees and February was 16 Degrees. The troops arrived at Valley Forge on the 19th of December and eight days later, the deepest single snow of the season fell, which was followed by the severest cold. They were plagued by boughts of cold, which would thaw and then refreeze. You can imagine what a muddy mess it would have been working on drills.
There were three continued snowstorms, but not of a blizzard-like quality. More moderate to heavy covering. "There was heavy snowfall" according to Dr. Muhlenberg on the 8th of February, "deeper now than we have had the whole winter," but was washed away by a heavy rainfall within the next 2 to 3 days. The heavy snowfall of the 8th, compounded by the heavy rainfall brought some flooding conditions...which made roads impassable.
Between the cold and freezing temperatures, there were even some above average warm temperatures during the encampment when some thaws set in. These included some days around Christmas and then approximately three periods in January lasting for several days at a time.
With a lack of proper clothing, and the inadequacies of the temporary military housing in the log huts, built during some foul weather, it was not a pleasant winter for the Continental Army. But through it all, they persevered, and we can thank them for our freedom.