Weather
Western Pennsylvania: First Frost Season Nears, Pittsburgh Average Is Oct. 10
Pittsburgh, PA – Western Pennsylvania is entering its typical first frost window, with cooler mornings arriving this week and colder spots northeast of Pittsburgh dipping into the upper 30s.
By Elliot Vaughn · 2026-10-04T12:57:09.338Z
Pittsburgh, PA – Western Pennsylvania is entering its typical first frost window, with cooler mornings arriving this week and colder spots northeast of Pittsburgh dipping into the upper 30s.
According to the National Weather Service in Pittsburgh, a dry cold front will pass Sunday night, followed by cooler mornings Tuesday and Wednesday. Some frost is possible, mainly across northeastern portions of the forecast area.
The change comes as much of western Pennsylvania enters the time of year when the first frost becomes increasingly common. NWS climatology shows Pittsburgh’s average first temperature of 36 degrees or lower is Oct. 10, while the average first freeze of 32 degrees or lower is Oct. 24.
Colder communities typically reach those milestones earlier. In DuBois, the average first 36 degree reading is Sept. 25, with the average first freeze around Oct. 9. The NWS notes that many climate sites across southwest Pennsylvania, eastern Ohio and northern West Virginia typically experience their first frost in late September or early October, while the first freeze generally follows during October.
That climatology does not mean frost or a freeze will occur on those exact dates. Actual conditions vary from year to year and by location.
For the immediate forecast, Tuesday morning lows are expected near 43 in Pittsburgh and around 40 in Latrobe. Butler could reach 39, while Indiana and Clarion are forecast around 38 and Punxsutawney near 37.
Oil City is also forecast around 38. Davis, West Virginia, could fall to about 35, among the coldest readings shown in the NWS forecast area.
Residents with frost sensitive plants should increasingly watch overnight forecasts as October progresses. For now, the best chance for frost Tuesday and Wednesday mornings is expected mainly northeast of Pittsburgh, rather than across the entire region.