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Will it freeze in Johnstown in the next 7 nights?
No overnight lows at or below 32°F are forecast in Johnstown during the next 7 nights in the available NWS frost forecast.
Tonight: forecast low 47°F. Above 36°F.
NWS forecast period: Thu, Nov 5, 6:00 PM EST to Fri, Nov 6, 6:00 AM EST.
5 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.
- Tonight 47°F Above 36°F · Partly Cloudy
- Fri, Nov 6 39°F Above 36°F · Chance Light Rain
- Sat, Nov 7 35°F Frost possible · Chance Light Rain
- Sun, Nov 8 33°F Frost possible · Mostly Clear then Slight Chance Rain Showers
- Mon, Nov 9 36°F Frost possible · Mostly Clear
- Tue, Nov 10 35°F Frost possible · Mostly Clear
- Wed, Nov 11 33°F Frost possible · Partly Cloudy
Overnight lows from the National Weather Service forecast for this location. This covers the available forecast window, not the first freeze of the whole season. Frost can form above 32°F on clear, calm nights.
Frost and freeze probabilities
Freeze dates shift from year to year. Spring percentages describe the chance of a freeze after the stated date; fall percentages describe the chance of a freeze by that date. The 10% spring date is the cautious one: a later freeze happens about 1 year in 10.
These dates describe historical probabilities, not this year’s forecast or the earliest and latest possible freezes. Different weather stations or probability thresholds can produce different published dates for the same city.
Average first hard freeze in Johnstown
The median first fall hard-freeze date (28°F) is November 2, from NOAA’s 1991–2020 Climate Normals at Johnstown Cambria County Airport. This is the 50% probability date, not a forecast for this year.
| Temperature | Last spring date 90% · 50% · 10% chance of a later freeze | First fall date 10% · 50% · 90% chance of an earlier freeze | Season |
|---|---|---|---|
| 36°F frost possible | Apr 22 · May 8 · May 24 | Sep 24 · Oct 8 · Oct 23 | 152 days |
| 32°F freeze | Apr 14 · Apr 29 · May 17 | Oct 5 · Oct 21 · Nov 5 | 176 days |
| 28°F hard freeze | Apr 1 · Apr 17 · May 5 | Oct 19 · Nov 2 · Nov 16 | 200 days |
Average high temperature by month
1991–2020 normals at Johnstown Cambria County Airport
Average low temperature by month
Months with lows near or below freezing carry frost risk
Where these frost dates come from
The frost dates for Johnstown, PA come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Johnstown Cambria County Airport (station USW00004726, elevation 2,284 ft), 4.5 mi from Johnstown. Local conditions (valleys, hilltops, distance to water, city heat) can shift frost dates by days or weeks. The hardiness zone is from the 2023 USDA Plant Hardiness Zone Map (USDA ARS and Oregon State University PRISM). See our methodology.
Frost dates near Johnstown
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Somerset, PA | 24 mi | May 2 | Oct 17 |
| Indiana, PA | 24 mi | May 8 | Oct 13 |
| Latrobe, PA | 24 mi | May 1 | Oct 13 |
| Hollidaysburg, PA | 29 mi | Apr 25 | Oct 20 |
| Altoona, PA | 30 mi | Apr 25 | Oct 21 |
| Greensburg, PA | 33 mi | May 1 | Oct 13 |
| Jeannette, PA | 37 mi | Apr 22 | Oct 25 |
| Murrysville, PA | 40 mi | Apr 22 | Oct 25 |
| Connellsville, PA | 42 mi | Apr 22 | Oct 27 |
| Punxsutawney, PA | 43 mi | May 10 | Oct 12 |
Frequently asked questions
When is the last frost in Johnstown?
On average, the last spring frost (32°F) in Johnstown is around April 29. In about 1 year in 10 it comes after May 17, and in 9 years in 10 it comes after April 14.
When is the first frost in Johnstown?
The first fall frost (32°F) usually arrives around October 21. There’s a 10% chance of a freeze by October 5 and a 90% chance by November 5.
Can it frost in Johnstown after the last frost date?
Yes. Frost can form on clear, calm nights even when the air stays above 32°F. Temperatures of 36°F or lower, cold enough for frost on exposed plants, have a 50% chance of occurring after May 8.
What growing zone is Johnstown?
Johnstown is in USDA Plant Hardiness Zone 6b (average annual extreme minimum temperature −5 to 0°F), based on the 2023 USDA map for ZIP code 15901. See growing zones in Pennsylvania.
More: all Pennsylvania frost dates · Pennsylvania growing zones · frost vs. freeze