Pittsburgh, Pennsylvania: planting zone & frost dates
Pittsburgh is in USDA plant hardiness zone 6b, where the average coldest winter night reaches -5 to 0°F (-20.6 to -17.8°C). The typical last spring frost is around Apr 24 and the first fall frost around Oct 22.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | May 6 | Oct 14 |
| Typical planning date (30% risk) | Apr 24 | Oct 22 |
| Median (50%) | Apr 18 | Oct 28 |
How to read this: after the spring "10% risk" date, a 32°F frost happens in only about 1 year in 10. In fall, the "10% risk" date is the early end — a frost before it happens about 1 year in 10.
Frost data comes from NOAA station PITTSBURGH ALLEGHENY CO AP, PA (USW00014762), 6.5 mi (10.5 km) from the city center and 279 ft higher than the city center (+85 m). Record used for the 1991–2020 normals: 22 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Pittsburgh
Pittsburgh spans more than one half-zone. Share of the city's land area by zone (via its 27 ZIP codes): 6b (86%), 7a (14%). The headline zone is the one covering the most land. Look up your ZIP for your exact zone.
ZIP codes in Pittsburgh and their zones
| ZIP | Zone | Share of city land |
|---|---|---|
| 15206 | 6b | 8.6% |
| 15212 | 6b | 8.0% |
| 15207 | 6b | 7.8% |
| 15210 | 6b | 7.5% |
| 15217 | 6b | 7.0% |
| 15214 | 6b | 5.5% |
| 15213 | 6b | 4.4% |
| 15220 | 6b | 4.1% |
| 15219 | 6b | 4.0% |
| 15205 | 6b | 3.9% |
| 15226 | 6b | 3.8% |
| 15201 | 7a | 3.5% |
| 15204 | 7a | 3.4% |
| 15216 | 6b | 3.3% |
| 15211 | 6b | 2.9% |
| 15224 | 6b | 2.8% |
| 15203 | 7a | 2.7% |
| 15208 | 6b | 2.7% |
| 15233 | 7a | 2.4% |
| 15236 | 6b | 1.9% |
| 15221 | 6b | 1.6% |
| 15222 | 7a | 1.6% |
| 15232 | 6b | 1.5% |
| 15120 | 6b | 1.1% |
| 15260 | 6b | 0.2% |
| 15282 | 6b | 0.2% |
| 15290 | 7a | 0.1% |
Vegetable planting calendar for Pittsburgh
Dates are counted from the 30%-risk frost dates above (last frost Apr 24, first frost Oct 22). Shift a week later in cold spots or low-lying ground.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Feb 27 – Mar 13 | May 1 – May 15 | — | — |
| Pepper | Feb 13 – Feb 27 | May 8 – May 22 | — | — |
| Lettuce | Mar 13 – Mar 27 | Apr 10 – May 1 | Mar 27 – May 8 | Aug 13 – Sep 10 |
| Green Beans | — | — | May 1 – Jun 5 | Jul 30 – Aug 13 |
| Sweet Corn | — | — | May 1 – May 29 | — |
| Zucchini & Summer Squash | Mar 27 – Apr 3 | May 1 – May 15 | May 1 – May 22 | Jul 30 – Aug 13 |
| Cucumber | Mar 27 – Apr 3 | May 8 – May 15 | May 1 – May 22 | Jul 30 – Aug 13 |
| Carrot | — | — | Apr 3 – May 8 | Jul 30 – Aug 13 |
| Onion | Jan 30 – Feb 13 | Mar 27 – Apr 10 | — | — |
| Potato | — | Mar 27 – Apr 17 | — | — |
| Basil | Mar 13 – Mar 27 | May 8 – May 22 | May 8 – May 29 | — |
| Spinach | — | — | Mar 13 – Apr 10 | Aug 27 – Sep 24 |
| Kale | Feb 27 – Mar 13 | Mar 27 – Apr 17 | Mar 27 – Apr 17 | Aug 13 – Sep 10 |
| Broccoli | Feb 27 – Mar 13 | Apr 10 – May 1 | — | Jul 30 – Aug 13 |
| Peas | — | — | Mar 13 – Apr 3 | Aug 13 – Aug 27 |
| Eggplant | Feb 13 – Feb 27 | May 8 – May 22 | — | — |
| Cabbage | Feb 27 – Mar 13 | Mar 27 – Apr 10 | — | Jul 30 – Aug 13 |
| Radish | — | — | Mar 20 – May 8 | Sep 10 – Oct 8 |
| Strawberry | — | Mar 27 – Apr 17 | — | — |
| Beets | — | — | Apr 3 – May 15 | Aug 13 – Aug 27 |
Nearby cities in Pennsylvania
- Erie — zone 6b, last frost May 2, first frost Oct 30
- Reading — zone 7a, last frost Apr 21, first frost Oct 22
- Allentown — zone 7a, last frost Apr 26, first frost Oct 17
- Bethlehem — zone 7a, last frost Apr 26, first frost Oct 17
- Philadelphia — zone 7b, last frost Apr 4, first frost Nov 11
More: all Pennsylvania cities · other zone 6b cities: Columbus, OH, Indianapolis, IN, Boston, MA, Detroit, MI, Kansas City, MO, Cincinnati, OH, Buffalo, NY, Toledo, OH
Pittsburgh gardening questions
When is the last frost in Pittsburgh, PA?
Plan around Apr 24. At NOAA's Pittsburgh Allegheny County Airport, PA station, 6.5 mi from the city center, there is a 30% chance of a 32°F frost after that date. Half of springs have their last frost by Apr 18, and after May 6 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Apr 5. The 90% and 10% dates are 34 days apart, close to the 36-day median for cities on this site.
When should I plant tomatoes in Pittsburgh, PA?
Start seeds indoors Feb 27 – Mar 13 and set transplants outside May 1 – May 15, once nights stay above 50°F and the soil is near 60°F. That leaves 181 days between the 30% frost dates, enough for most varieties including 80–85-day slicers. More: tomato planting dates by zone.
How long is the growing season in Pittsburgh?
About 193 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 171 days, and in 1 year in 10 it runs 212 days or more. In fall there is a 10% chance of frost by Oct 14 and a 30% chance by Oct 22. That ranks 3rd longest of 6 Pennsylvania cities on this site.
When should I plant a fall garden in Pittsburgh?
Count back from the first fall frost (Oct 22): transplant broccoli Jul 30 – Aug 13; sow kale Aug 13 – Sep 10; sow lettuce Aug 13 – Sep 10; sow radishes Sep 10 – Oct 8. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Nov 8. How the math works: succession and fall planting.
Did Pittsburgh's hardiness zone change on the 2023 map?
No. Going by the zone that covers most of the city's land, Pittsburgh is zone 6b on both the 2012 and the 2023 USDA maps (PRISM/OSU ZIP listings). About 42% of U.S. ZIP codes kept their half-zone in 2023. Why the 2023 map is warmer.
Is all of Pittsburgh in zone 6b?
No. Zone 6b covers about 86% of the city's land; the rest is in 7a (14%), measured across the city's 27 ZIP codes. Check your own ZIP code in the table above or with the ZIP lookup.