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Will it freeze in Swissvale in the next 7 nights?
No overnight lows at or below 32°F are forecast in Swissvale during the next 7 nights in the available NWS frost forecast.
Tonight: forecast low 48°F. Above 36°F.
NWS forecast period: Thu, Nov 5, 6:00 PM EST to Fri, Nov 6, 6:00 AM EST.
2 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.
- Tonight 48°F Above 36°F · Partly Cloudy
- Fri, Nov 6 40°F Above 36°F · Chance Light Rain
- Sat, Nov 7 38°F Above 36°F · Chance Light Rain then Mostly Cloudy
- Sun, Nov 8 36°F Frost possible · Mostly Clear
- Mon, Nov 9 38°F Above 36°F · Mostly Clear
- Tue, Nov 10 38°F Above 36°F · Mostly Clear
- Wed, Nov 11 36°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 Swissvale
The median first fall hard-freeze date (28°F) is November 23, from NOAA’s 1991–2020 Climate Normals at Braddock Lock 2. 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 3 · Apr 20 · May 11 | Oct 13 · Oct 29 · Nov 12 | 189 days |
| 32°F freeze | Mar 22 · Apr 5 · Apr 22 | Oct 28 · Nov 10 · Nov 27 | 219 days |
| 28°F hard freeze | Mar 12 · Mar 27 · Apr 9 | Nov 6 · Nov 23 · Dec 10 | 241 days |
Average high temperature by month
1991–2020 normals at Braddock Lock 2
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 Swissvale, PA come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Braddock Lock 2 (station USC00360861, elevation 730 ft), 2.4 mi from Swissvale. 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 Swissvale
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Forest Hills, PA | 1.9 mi | Apr 5 | Nov 10 |
| Wilkinsburg, PA | 1.9 mi | Apr 5 | Nov 10 |
| Munhall, PA | 1.9 mi | Apr 5 | Nov 10 |
| Duquesne, PA | 3.7 mi | Apr 5 | Nov 10 |
| Baldwin, PA | 4.3 mi | Apr 18 | Oct 28 |
| West Mifflin, PA | 4.3 mi | Apr 18 | Oct 28 |
| Pittsburgh, PA | 5.0 mi | Apr 18 | Oct 28 |
| Penn Hills, PA | 5.0 mi | Apr 16 | Nov 1 |
| Brentwood, PA | 5.6 mi | Apr 18 | Oct 28 |
| McKeesport, PA | 5.6 mi | May 2 | Oct 20 |
Frequently asked questions
When is the last frost in Swissvale?
On average, the last spring frost (32°F) in Swissvale is around April 5. In about 1 year in 10 it comes after April 22, and in 9 years in 10 it comes after March 22.
When is the first frost in Swissvale?
The first fall frost (32°F) usually arrives around November 10. There’s a 10% chance of a freeze by October 28 and a 90% chance by November 27.
Can it frost in Swissvale 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 April 20.
What growing zone is Swissvale?
Swissvale 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 15218. See growing zones in Pennsylvania.
More: all Pennsylvania frost dates · Pennsylvania growing zones · frost vs. freeze