Frost dates 2026–2027

Frost dates for Coraopolis, Pennsylvania

Median (50% chance) dates of the last and first 32°F frost, from NOAA 1991–2020 climate normals at Moon Twp, 3.2 mi away (close match).

Last spring frostApr 28
First fall frostOct 18
172 frost-free days
Last spring frostApr 281 year in 10 after May 15
First fall frostOct 181 year in 10 by Oct 5
Growing season172 daysbetween median 32°F dates
Hardiness zoneZone 6b−5 to 0°F average extreme low

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Will it freeze in Coraopolis in the next 7 nights?

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

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 Coraopolis

The median first fall hard-freeze date (28°F) is October 31, from NOAA’s 1991–2020 Climate Normals at Moon Twp. 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 23 · May 7 · May 23 Sep 26 · Oct 7 · Oct 22 153 days
32°F freeze Apr 15 · Apr 28 · May 15 Oct 5 · Oct 18 · Nov 4 172 days
28°F hard freeze Apr 1 · Apr 17 · May 1 Oct 13 · Oct 31 · Nov 17 195 days
NOAA NCEI U.S. Climate Normals 1991–2020, station USC00365918. How to read these probabilities.

Average high temperature by month

1991–2020 normals at Moon Twp

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 Coraopolis, PA come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Moon Twp (station USC00365918, elevation 1,172 ft), 3.2 mi from Coraopolis. 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 Coraopolis

CityDistanceLast spring frostFirst fall frost
Bellevue, PA 5.6 mi Apr 24 Oct 27
McKees Rocks, PA 6.2 mi Apr 24 Oct 27
Franklin Park, PA 6.2 mi Apr 24 Oct 27
Ambridge, PA 6.2 mi Apr 8 Nov 8
West View, PA 6.8 mi Apr 24 Oct 27
Crafton, PA 7.5 mi Apr 24 Oct 27
Carnegie, PA 8.1 mi Apr 24 Oct 27
Aliquippa, PA 8.7 mi Apr 8 Nov 8
Economy, PA 8.7 mi Apr 8 Nov 8
Dormont, PA 11 mi Apr 18 Oct 28

Frequently asked questions

When is the last frost in Coraopolis?

On average, the last spring frost (32°F) in Coraopolis is around April 28. In about 1 year in 10 it comes after May 15, and in 9 years in 10 it comes after April 15.

When is the first frost in Coraopolis?

The first fall frost (32°F) usually arrives around October 18. There’s a 10% chance of a freeze by October 5 and a 90% chance by November 4.

Can it frost in Coraopolis 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 7.

What growing zone is Coraopolis?

Coraopolis 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 15108. See growing zones in Pennsylvania.

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