When to plant in Harrisburg, PA
USDA Zone 7aHarrisburg, Pennsylvania frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
Zone 7a means many perennials and even some tender shrubs overwinter in Harrisburg, while your frost dates still decide when annuals go out.
Frost probability
HARRISBURG 1 NE · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Harrisburg’s own odds, recorded at HARRISBURG 1 NE.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 15 | Apr 30 | Apr 14 | Sep 28 | Oct 12 | Oct 28 |
| 32°F | May 2 | Apr 15 | Apr 1 | Oct 7 | Oct 23 | Nov 7 |
| 28°F | Apr 16 | Apr 3 | Mar 19 | Oct 20 | Nov 5 | Nov 21 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Harrisburg, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 14 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Harrisburg planting FAQ
When is the last spring frost in Harrisburg, PA?
Plan for the last spring frost in Harrisburg around April 15 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in Harrisburg, PA?
The first fall frost in Harrisburg typically arrives around October 23 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Harrisburg in?
Harrisburg is in USDA hardiness zone 7a. In zone 7a, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Harrisburg?
There are roughly 191 frost-free days in Harrisburg (a moderate growing season), running from the average last frost around April 15 to the first fall frost near October 23.
When should I plant tomatoes in Harrisburg?
In Harrisburg, start tomato seeds indoors around February 18–March 4, then transplant seedlings outdoors around April 22 once the danger of frost has passed.
Never miss a window in Harrisburg
An email when it’s time to start seeds, transplant, and sow — timed to Harrisburg’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Progress · 4 km
- Colonial Park · 7 km
- Hershey · 20 km
- Elizabethtown · 28 km
- Carlisle · 28 km
- Weigelstown · 33 km
- Shiloh · 35 km
- York · 37 km
Frost dates recorded at HARRISBURG 1 NE, 1 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Harrisburg, PA — Frost Dates & Zone 7a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00363698. Retrieved from https://blissgarden.com/pennsylvania/harrisburg.