Winter in Philly Shines: Snow, Cold and Surprising Forecast Fumbles

The city of Philadelphia faced a winter that was colder and snowier than most people expected. From the start of December until the end of February, temperatures dipped below 33 degrees on average – one of the lowest in more than a century. Snow fell over 20 inches, putting Philly in the top twenty percent of all recorded winters for snowfall. Most weather forecasts predicted a milder season. Some gave the city around 15 to 18 inches of snow, while others expected about 23 inches. Even the temperature outlooks leaned toward normal or slightly warmer than average, except for one private forecast that called for cooler weather. Yet the reality was far different: Philly got 30 inches of snow, a dramatic 150 percent increase over the usual amount. Why did this happen? Scientists point to a long‑lasting high‑pressure block over Greenland. This “blocking” pattern kept cold air and storms trapped in the eastern United States, while the western states stayed relatively warm. The block also influenced the Arctic Oscillation – a pattern that normally balances cold air between the north and south. For most of winter, the oscillation stayed in its negative phase, allowing cold air to spill farther south than usual.The blocking was likely linked to the loss of sea ice near Greenland. When ice melts, water absorbs more solar energy and can alter pressure patterns in the upper atmosphere. Although the planet is still about 2 degrees Fahrenheit warmer than it was a century ago, these changes in sea ice and pressure can create unusually cold pockets. Philadelphia’s winter of 2025–26 also fits into a longer trend. In the early 2000s, winters in the city have generally been warmer than the long‑term average. That trend led forecasters to expect above‑normal temperatures for several consecutive years. In reality, the city saw colder than average days during this season, proving that long‑term trends can sometimes mislead short‑term predictions. The unexpected cold and heavy snowfall have reminded scientists and residents alike that weather can still surprise us. Even when forecasts seem reliable, unusual atmospheric conditions can turn a mild winter into one of the coldest and snowiest on record.