Frost dates 2026–2027

Frost dates for Mount Pleasant, Iowa

Median (50% chance) dates of the last and first 32°F frost, from NOAA 1991–2020 climate normals at Mt Pleasant 1 Ssw, 1.3 mi away (close match).

Last spring frostApr 30
First fall frostOct 10
163 frost-free days
Last spring frostApr 301 year in 10 after May 14
First fall frostOct 101 year in 10 by Sep 24
Growing season163 daysbetween median 32°F dates
Hardiness zoneZone 5b−15 to −10°F average extreme low

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Will it freeze in Mount Pleasant in the next 7 nights?

The earliest overnight low at or below 32°F in the available NWS frost forecast is Fri, Nov 6: 27°F (Fri, Nov 6, 6:00 PM CST to Sat, Nov 7, 6:00 AM CST).

Tonight: forecast low 39°F. Above 36°F.

NWS forecast period: Thu, Nov 5, 6:00 PM CST to Fri, Nov 6, 6:00 AM CST.

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 Mount Pleasant

The median first fall hard-freeze date (28°F) is October 20, from NOAA’s 1991–2020 Climate Normals at Mt Pleasant 1 Ssw. 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 25 · May 9 · May 23 Sep 16 · Oct 1 · Oct 13 144 days
32°F freeze Apr 13 · Apr 30 · May 14 Sep 24 · Oct 10 · Oct 23 163 days
28°F hard freeze Apr 3 · Apr 17 · May 5 Oct 3 · Oct 20 · Nov 2 185 days
NOAA NCEI U.S. Climate Normals 1991–2020, station USC00135796. How to read these probabilities.

Average high temperature by month

1991–2020 normals at Mt Pleasant 1 Ssw

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 Mount Pleasant, IA come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Mt Pleasant 1 Ssw (station USC00135796, elevation 730 ft), 1.3 mi from Mount Pleasant. 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 Mount Pleasant

CityDistanceLast spring frostFirst fall frost
Fairfield, IA 22 mi Apr 27 Oct 12
Washington, IA 24 mi Apr 28 Oct 11
Burlington, IA 25 mi Apr 15 Oct 20
Fort Madison, IA 25 mi Apr 12 Oct 25
Keokuk, IA 39 mi Apr 10 Oct 27
Muscatine, IA 40 mi Apr 24 Oct 14
Ottumwa, IA 46 mi Apr 23 Oct 14
Monmouth, IL 47 mi Apr 22 Oct 15
Iowa City, IA 48 mi Apr 21 Oct 18
Coralville, IA 51 mi Apr 21 Oct 18

Frequently asked questions

When is the last frost in Mount Pleasant?

On average, the last spring frost (32°F) in Mount Pleasant is around April 30. In about 1 year in 10 it comes after May 14, and in 9 years in 10 it comes after April 13.

When is the first frost in Mount Pleasant?

The first fall frost (32°F) usually arrives around October 10. There’s a 10% chance of a freeze by September 24 and a 90% chance by October 23.

Can it frost in Mount Pleasant 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 9.

What growing zone is Mount Pleasant?

Mount Pleasant is in USDA Plant Hardiness Zone 5b (average annual extreme minimum temperature −15 to −10°F), based on the 2023 USDA map for ZIP code 52641. See growing zones in Iowa.

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