When Do Pipes Freeze in Pennsylvania? Freeze Dates for Every Town

Pipes do not freeze on a calendar date. They freeze on the first night the air in an unheated crawlspace, garage or exterior wall stays below about 20°F for a few hours, and in Pennsylvania that night arrives at a different time in every town. The table below gives the typical first frost, the freeze nights and the sub-zero days for every Pennsylvania town we cover, all 805 of them, from ten years of Daymet climate data.

Pennsylvania at a glance

What the numbers mean for your pipes

Freeze nights count every night the low drops below 32°F. Most of them hurt nothing. The ones that do are the first hard freeze of the season, when a hose is still connected and the crawlspace vents are still open, and the deep cold snap in January when a line along an exterior wall finally loses its margin. Sub-zero days are the second number to watch: below 0°F even an insulated line in an unheated space can freeze. The first frost date is the median of ten years, so about half the years frost earlier and half later.

When a freeze does find a pipe, call to get help from Pennsylvania expert plumbers in 2 minutes. Before it does, how to prevent frozen pipes and the pipe freeze risk checker cover the prep.

Every Pennsylvania town we cover

Climate data: Daymet, NASA/ORNL, 2015–2024. Typical values over ten years, not a forecast.