Frost dates for 15907Johnstown, PA
The average last spring frost in Johnstown is May 8 and the average first fall frost is October 13, giving a typical growing season of about 157 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 8
- Average first fall frost
- Oct 13
- Growing season
- 157 days
Safer after May 24 (1-in-10 risk)
Possible by Oct 1 (1-in-10 risk)
Last frost typically in 186 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | May 4 · May 20 · Jun 2 | Sep 19 · Oct 3 · Oct 15 | 135 days | 100% |
| Frost / freeze (32°F) | Apr 23 · May 8 · May 24 | Oct 1 · Oct 13 · Oct 27 | 157 days | 100% |
| Hard freeze (28°F) | Apr 13 · Apr 27 · May 14 | Oct 9 · Oct 25 · Nov 7 | 180 days | 100% |
Planting calendar for Johnstown
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Apr 7 – Jun 13 |
| Tomatoes | Transplant outdoors | May 24 – Jun 23 |
| Peppers | Start seeds indoors | Apr 7 – May 8 |
| Peppers | Transplant outdoors | Jun 7 – Jul 8 |
| Eggplant | Start seeds indoors | Apr 24 – May 23 |
| Eggplant | Transplant outdoors | Jun 7 – Jul 8 |
| Cucumbers | Sow outdoors | Jun 7 – Jul 3 |
| Summer squash | Sow outdoors | May 24 – Jul 8 |
| Winter squash & pumpkins | Sow outdoors | Jun 7 – Jul 8 |
| Snap beans | Sow outdoors | May 24 – Jul 26 |
| Sweet corn | Sow outdoors | May 24 – Jun 23 |
| Watermelon & cantaloupe | Sow outdoors | Jun 7 – Jul 8 |
| Okra | Sow outdoors | May 31 – Jun 23 |
| Peas | Sow outdoors (spring) | Apr 7 – May 23 |
| Potatoes | Plant outdoors (spring) | Apr 7 – Jun 7 |
| Onions | Start seeds indoors (spring) | Feb 24 – Mar 23 |
| Onions | Transplant outdoors (spring) | Apr 24 – May 23 |
| Broccoli | Start seeds indoors (spring) | Mar 20 – Apr 23 |
| Broccoli | Transplant outdoors (spring) | Apr 24 – May 23 |
| Broccoli | Start seeds indoors (fall) | Jun 13 – Jun 23 |
| Broccoli | Transplant outdoors (fall) | Jul 13 – Jul 24 |
| Cabbage | Start seeds indoors (spring) | Mar 10 – Apr 7 |
| Cabbage | Transplant outdoors (spring) | Apr 7 – May 8 |
| Cabbage | Start seeds indoors (fall) | Jun 3 – Jul 3 |
| Cabbage | Transplant outdoors (fall) | Jul 3 – Aug 3 |
| Leaf lettuce | Sow outdoors (spring) | Apr 7 – Jun 23 |
| Leaf lettuce | Sow outdoors (fall) | Jul 3 – Aug 19 |
| Spinach | Sow outdoors (spring) | Mar 31 – May 14 |
| Spinach | Sow outdoors (fall) | Jul 20 – Aug 24 |
| Radishes | Sow outdoors (spring) | Apr 7 – May 28 |
| Radishes | Sow outdoors (fall) | Jul 3 – Sep 3 |
| Kale | Sow outdoors (spring) | Apr 24 – May 14 |
| Kale | Sow outdoors (fall) | Jun 26 – Aug 3 |
| Carrots | Sow outdoors (spring) | May 8 – Jun 23 |
| Carrots | Sow outdoors (fall) | Jun 3 – Jul 19 |
| Garlic | Plant outdoors (fall) | Oct 3 – Nov 3 |
Where these dates come from
ZIP code 15907 is matched to the NOAA station Indiana 3 Se, PA, 34.8 km away, at 1,102 ft elevation (69 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Indiana 3 Se, PA (used) | 1,102 ft | May 8 | Oct 13 |
| Johnstown Cambria Co Ap, PA | 2,284 ft | Apr 29 | Oct 21 |
| Ebensburg Sewage Plt, PA | 1,940 ft | May 17 | Oct 2 |
| Laurel Summit, PA | 2,730 ft | May 6 | Oct 12 |
Frost dates near Johnstown
- Johnstown, PA 15901 · last May 8, first Oct 13
- Parkhill, PA 15945 · last May 17, first Oct 2
- Tire Hill, PA 15959 · last May 4, first Oct 10
- Mineral Point, PA 15942 · last Apr 25, first Oct 21
- Hollsopple, PA 15935 · last Apr 29, first Oct 21
- Elton, PA 15934 · last Apr 29, first Oct 21
- Davidsville, PA 15928 · last Apr 29, first Oct 21
- South Fork, PA 15956 · last May 17, first Oct 2
Frequently asked questions
- When is the last frost in Johnstown, PA?
- For ZIP code 15907, the average last spring frost (32°F) is May 8, based on NOAA 1991-2020 climate normals for the Indiana 3 Se, PA weather station. There is a 1-in-10 chance of a frost after May 24.
- When is the first frost in Johnstown, PA?
- The average first fall frost (32°F) is October 13. There is a 1-in-10 chance of frost by October 1, so tender plants are at risk from that point on.
- How long is the growing season in 15907?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 157 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.