First & Last Frost Dates in Pennsylvania (2026)
Typical first freeze October 10 · last spring frost April 30 · about 165 growing days between them.
First frost approaching — typically 12 days outWhere Pennsylvania sits on the frost line
NOAA 1991 to 2020 normalsThe Allegheny Plateau's "icebox" towns like Bradford see frost six weeks before Philadelphia — Pennsylvania's spread is bigger than most states'.
Frost dates for your exact ZIP
The dates above are the state median. Enter a ZIP code to snap to the nearest of 150 NOAA reference stations and read that station’s own first and last freeze instead:
Frost dates across Pennsylvania
State averages hide huge local spread — elevation, cold-air drainage, urban heat, and nearby water routinely move frost dates by two to four weeks within the same state. Median dates for representative Pennsylvania stations:
| City | Typical first frost | Typical last frost |
|---|---|---|
| Philadelphia | November 2 | April 5 |
| Pittsburgh | October 20 | April 22 |
| Bradford | September 18 | May 26 |
Not near these cities? The ZIP lookup above snaps any US address to its nearest reference station. It is the same tool as the site’s national frost date lookup.
Your Pennsylvania first-frost playbook
The Pennsylvania planting calendar
Every date below is computed from Pennsylvania’s own frost anchors — last frost ~April 30, first frost ~October 10 — using the standard week-count rules seed packets assume. Shift everything a few days for your microclimate (see the city table above).
| Garden task | Typical Pennsylvania date | The rule it comes from |
|---|---|---|
| Start onions & leeks indoors | February 19 | ~10 weeks before last frost |
| Start peppers & tomatoes indoors | March 5 | ~8 weeks before last frost |
| Direct-sow peas & spinach | March 26 | ~5 weeks before last frost |
| Plant potatoes | April 16 | ~2 weeks before last frost |
| Transplant tomatoes & peppers out | May 25 | ~1 week after the late frost date |
| Sow fall carrots (70-day) | July 17 | ~12 weeks before first frost |
| Sow fall spinach & lettuce | August 21 | ~7 weeks before first frost |
| Plant garlic | October 24 | ~2 weeks after first frost |
Two rules do most of the work: count backward from first frost for fall crops (a 70-day carrot needs sowing ~12 weeks out, because fall growth slows as days shorten), and count forward from the late last-frost date — not the median — for anything frost-tender going outside.
What dies at what temperature
“Frost” isn’t one event. Surfaces can frost with air temps as high as 36–37°F on calm clear nights; a freeze is 32°F; a hard freeze is 28°F and ends the season for anything unprotected. Crops check out at very different points along the way:
| Crops | Damage point | What it means |
|---|---|---|
| Basil, impatiens, coleus, sweet potato vine | 38–40°F | Damaged before an official frost even hits |
| Tomatoes, peppers, cucumbers, squash, beans | 32°F | Killed by the first light freeze |
| Lettuce, chard, cilantro, peas | 28°F | Shrug off light frost; done at a hard freeze |
| Broccoli, cabbage, carrots, beets | 25°F | Keep producing weeks past first frost |
| Kale, spinach, Brussels sprouts, parsnips | 15–20°F | Frost makes them sweeter — harvest all late fall |
The practical read for Pennsylvania: once you’re inside the September 22–October 30 window, the top two rows are living on borrowed time — while the bottom two rows are just getting started. Frost converts starches to sugars in kale, carrots, and parsnips; the sweetest harvests of the year come after first frost.
Pennsylvania frost date FAQ
Plan the rest of the season
More Northeast frost dates
Dates are median first/last 32°F freeze approximations from NOAA 1991–2020 climate normals for representative stations, bracketed by roughly the 10%/90% range. Any single year varies; microclimates vary more. National picture: first frost dates for every state