Frost dates 2026–2027

Frost dates for McKeesport, Pennsylvania

Median (50% chance) dates of the last and first 32°F frost, from NOAA 1991–2020 climate normals at Mckeesport, 0.8 mi away (close match).

Last spring frostMay 2
First fall frostOct 20
170 frost-free days
Last spring frostMay 21 year in 10 after May 20
First fall frostOct 201 year in 10 by Oct 1
Growing season170 daysbetween median 32°F dates
Hardiness zoneZone 6b−5 to 0°F average extreme low

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Will it freeze in McKeesport in the next 7 nights?

No overnight lows at or below 32°F are forecast in McKeesport 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.

3 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.

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 McKeesport

The median first fall hard-freeze date (28°F) is November 1, from NOAA’s 1991–2020 Climate Normals at Mckeesport. This is the 50% probability date, not a forecast for this year.

TemperatureLast 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 26 · May 12 · May 27 Sep 21 · Oct 7 · Oct 24 149 days
32°F freeze Apr 17 · May 2 · May 20 Oct 1 · Oct 20 · Nov 3 170 days
28°F hard freeze Apr 2 · Apr 20 · May 10 Oct 10 · Nov 1 · Nov 14 194 days
NOAA NCEI U.S. Climate Normals 1991–2020, station USC00365573. How to read these probabilities.

Average high temperature by month

1991–2020 normals at Mckeesport

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 McKeesport, PA come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Mckeesport (station USC00365573, elevation 740 ft), 0.8 mi from McKeesport. 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 McKeesport

CityDistanceLast spring frostFirst fall frost
Duquesne, PA 2.5 mi Apr 5 Nov 10
White Oak, PA 2.5 mi May 2 Oct 20
West Mifflin, PA 3.1 mi Apr 18 Oct 28
Clairton, PA 3.7 mi May 2 Oct 20
Munhall, PA 4.3 mi Apr 5 Nov 10
Forest Hills, PA 5.6 mi Apr 5 Nov 10
Swissvale, PA 5.6 mi Apr 5 Nov 10
Baldwin, PA 6.2 mi Apr 18 Oct 28
Jefferson Hills, PA 6.2 mi Apr 18 Oct 28
Pleasant Hills, PA 6.2 mi Apr 18 Oct 28

Frequently asked questions

When is the last frost in McKeesport?

On average, the last spring frost (32°F) in McKeesport is around May 2. In about 1 year in 10 it comes after May 20, and in 9 years in 10 it comes after April 17.

When is the first frost in McKeesport?

The first fall frost (32°F) usually arrives around October 20. There’s a 10% chance of a freeze by October 1 and a 90% chance by November 3.

Can it frost in McKeesport 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 12.

What growing zone is McKeesport?

McKeesport 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 15132. See growing zones in Pennsylvania.

More: all Pennsylvania frost dates · Pennsylvania growing zones · frost vs. freeze