Frost Dates for Altoona, PA
In Altoona, PA, the average last spring frost is around Apr 25 and the average first fall frost around Oct 21, for a growing season of about 176 days. For frost-tender plants, wait until May 11, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Altoona 3 W, PA weather station, 4 miles away, elevation 1,320 ft. Frost can come earlier in low spots and valleys and later near cities and large lakes.
Frost probability by date
Chance of a 32°F frost after the spring date, or before the fall date.
| Chance | Last spring frost | First fall frost |
|---|---|---|
| 10% | May 11 | Oct 5 |
| 20% | May 6 | Oct 10 |
| 30% | May 1 | Oct 15 |
| 40% | Apr 29 | Oct 18 |
| 50% | Apr 25 | Oct 21 |
| 60% | Apr 22 | Oct 24 |
| 70% | Apr 19 | Oct 27 |
| 80% | Apr 15 | Nov 1 |
| 90% | Apr 10 | Nov 5 |
Light frost vs. hard freeze
Average (50%) dates for each temperature. Tender plants are damaged at 36°F; most hardy crops survive until 28°F.
| Temperature | Last in spring | First in fall |
|---|---|---|
| Light frost (36°F) | May 4 | Oct 8 |
| Frost / freeze (32°F) | Apr 25 | Oct 21 |
| Hard freeze (28°F) | Apr 13 | Nov 3 |
Planting calendar for Altoona
Transplant May 2 – May 16
Transplant May 9 – May 23
Transplant May 9 – May 23
Transplant May 2 – May 16
Sow or transplant May 2 – May 16
Sow or transplant May 2 – May 16
Sow or transplant May 9 – May 23
Sow or transplant Mar 28 – Apr 11
Fall sowing Aug 26 – Sep 23
Fall sowing Aug 26 – Sep 16
Fall sowing Aug 12 – Aug 26
Sow or transplant Mar 28 – Apr 11
Fall sowing Aug 12 – Sep 9
Transplant Apr 11 – Apr 25
Fall sowing Jul 29 – Aug 12
Transplant Apr 4 – Apr 18
Fall sowing Jul 29 – Aug 12
Fall sowing Jul 29 – Aug 12
Fall sowing Sep 9 – Sep 30
Fall sowing Aug 12 – Aug 26
Plant Mar 28 – Apr 11
Based on the average last frost (Apr 25) and first frost (Oct 21). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.