Frost dates 2026–2027

Frost dates for Altoona, Pennsylvania

Median (50% chance) dates of the last and first 32°F frost, from NOAA 1991–2020 climate normals at Altoona 3 W, 3.5 mi away (close match).

Last spring frostApr 25
First fall frostOct 21
176 frost-free days
Last spring frostApr 251 year in 10 after May 11
First fall frostOct 211 year in 10 by Oct 5
Growing season176 daysbetween median 32°F dates
Hardiness zoneZone 6b−5 to 0°F average extreme low

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Will it freeze in Altoona in the next 7 nights?

The earliest overnight low at or below 32°F in the available NWS frost forecast is Wed, Nov 11: 32°F (Wed, Nov 11, 6:00 PM EST to Thu, Nov 12, 6:00 AM EST).

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.

4 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 Altoona

The median first fall hard-freeze date (28°F) is November 3, from NOAA’s 1991–2020 Climate Normals at Altoona 3 W. 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 21 · May 4 · May 22 Sep 26 · Oct 8 · Oct 21 155 days
32°F freeze Apr 10 · Apr 25 · May 11 Oct 5 · Oct 21 · Nov 5 176 days
28°F hard freeze Apr 1 · Apr 13 · May 1 Oct 19 · Nov 3 · Nov 17 202 days
NOAA NCEI U.S. Climate Normals 1991–2020, station USC00360140. How to read these probabilities.

Average high temperature by month

1991–2020 normals at Altoona 3 W

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 Altoona, PA come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Altoona 3 W (station USC00360140, elevation 1,320 ft), 3.5 mi from Altoona. 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 Altoona

CityDistanceLast spring frostFirst fall frost
Hollidaysburg, PA 5.6 mi Apr 25 Oct 20
Tyrone, PA 14 mi May 13 Oct 1
Huntingdon, PA 21 mi Apr 19 Oct 28
Johnstown, PA 30 mi Apr 29 Oct 21
State College, PA 35 mi Apr 20 Oct 26
Clearfield, PA 35 mi May 4 Oct 11
Indiana, PA 40 mi May 8 Oct 13
Punxsutawney, PA 42 mi May 10 Oct 12
Bellefonte, PA 43 mi Apr 20 Oct 26
Lewistown, PA 44 mi Apr 21 Oct 24

Frequently asked questions

When is the last frost in Altoona?

On average, the last spring frost (32°F) in Altoona is around April 25. In about 1 year in 10 it comes after May 11, and in 9 years in 10 it comes after April 10.

When is the first frost in Altoona?

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 Altoona 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 4.

What growing zone is Altoona?

Altoona 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 16602. See growing zones in Pennsylvania.

More: all Pennsylvania frost dates · Pennsylvania growing zones · UV index today in Altoona · frost vs. freeze