Altoona, PA planting zone & frost dates

Altoona is in USDA hardiness zone 6b. The last spring frost usually comes around April 25 and the first fall frost around October 21, for a growing season of about 176 days.

USDA hardiness zone6bavg. extreme winter low -5°F to 0°F
Average last spring frostApril 2590% chance of no frost after May 11
Average first fall frostOctober 2110% chance of frost by October 5
Growing season176 daysfrost-free days in an average year

Planting calendar for Altoona

Dates are counted from the average last spring frost (April 25) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.

CropWhen
TomatoesStart seeds indoors: Feb 28 – Mar 14
Transplant outdoors: May 2 – May 9
PeppersStart seeds indoors: Feb 14 – Feb 28
Transplant outdoors: May 9 – May 16
EggplantStart seeds indoors: Feb 14 – Feb 28
Transplant outdoors: May 9 – May 16
BroccoliStart seeds indoors: Feb 14 – Feb 28
Transplant outdoors: Mar 28 – Apr 11
CabbageStart seeds indoors: Feb 14 – Feb 28
Transplant outdoors: Mar 28 – Apr 11
Onions (sets)Plant outdoors: Mar 28 – Apr 11
PeasSow outdoors: Mar 14 – Mar 28
SpinachSow outdoors: Mar 14 – Mar 28
LettuceSow outdoors: Mar 28 – Apr 11
CarrotsSow outdoors: Mar 28 – Apr 11
PotatoesPlant outdoors: Mar 28 – Apr 11
BeansSow outdoors: May 2 – May 9
Sweet cornSow outdoors: May 2 – May 9
CucumbersSow outdoors: May 2 – May 9
Squash & zucchiniSow outdoors: May 2 – May 9
BasilStart seeds indoors: Mar 14 – Mar 28
Transplant outdoors: May 2 – May 9

Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 26 (8 weeks before the average first fall frost on Oct 21).

Useful for zone 6b gardens

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Frost risk in detail

90% chance50% chance10% chance
Last 32°F frost in spring is afterApr 10Apr 25May 11
First 32°F frost in fall is beforeNov 5Oct 21Oct 5

How to read it: in spring there is a 10% chance of a frost after May 11, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 5. A hard freeze (28°F) usually ends around April 13.

Hardiness zone by ZIP code in Altoona

Nearby cities

All cities in Pennsylvania → · Other zone 6b cities →

Questions

What growing zone is Altoona, PA?

Altoona is in USDA Plant Hardiness Zone 6b (average extreme winter low -5°F to 0°F), according to the USDA 2023 map.

When is the last frost in Altoona?

The average last spring frost (32°F) in Altoona is April 25. There is still a 10% chance of frost until May 11.

When can I plant tomatoes in Altoona?

Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 2 – May 9. Start seeds indoors 6–8 weeks before the last frost.

Frost dates: NOAA U.S. Climate Normals 1991–2020, station Altoona 3 W, PA (USC00360140), 6.6 km (4.1 mi) from the city center, elevation 402 m, based on 29 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.