Frost dates 2026–2027

Frost dates for Platteville, Wisconsin

Median (50% chance) dates of the last and first 32°F frost, from NOAA 1991–2020 climate normals at Platteville, 1.4 mi away (close match).

Last spring frostApr 30
First fall frostOct 13
166 frost-free days
Last spring frostApr 301 year in 10 after May 13
First fall frostOct 131 year in 10 by Sep 29
Growing season166 daysbetween median 32°F dates
Hardiness zoneZone 5a−20 to −15°F average extreme low

Checking current alerts… View NWS forecast and alerts.

Will it freeze in Platteville in the next 7 nights?

The earliest overnight low at or below 32°F in the available NWS frost forecast is Fri, Nov 6: 26°F (Fri, Nov 6, 6:00 PM CST to Sat, Nov 7, 6:00 AM CST).

Tonight: forecast low 35°F. Frost possible.

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

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 Platteville

The median first fall hard-freeze date (28°F) is October 22, from NOAA’s 1991–2020 Climate Normals at Platteville. 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 8 · May 23 Sep 20 · Oct 3 · Oct 14 146 days
32°F freeze Apr 14 · Apr 30 · May 13 Sep 29 · Oct 13 · Oct 24 166 days
28°F hard freeze Apr 3 · Apr 17 · May 2 Oct 9 · Oct 22 · Nov 3 187 days
NOAA NCEI U.S. Climate Normals 1991–2020, station USC00476646. How to read these probabilities.

Average high temperature by month

1991–2020 normals at Platteville

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 Platteville, WI come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Platteville (station USC00476646, elevation 990 ft), 1.4 mi from Platteville. 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 Platteville

CityDistanceLast spring frostFirst fall frost
Dubuque, IA 20 mi Apr 19 Oct 21
Asbury, IA 22 mi Apr 19 Oct 21
Dodgeville, WI 24 mi May 3 Oct 7
Prairie du Chien, WI 40 mi Apr 28 Oct 12
Mount Horeb, WI 42 mi May 7 Oct 1
Richland Center, WI 42 mi May 5 Oct 6
Monroe, WI 43 mi Apr 27 Oct 14
Maquoketa, IA 47 mi Apr 25 Oct 14
Verona, WI 50 mi Apr 28 Oct 15
Freeport, IL 52 mi Apr 26 Oct 13

Frequently asked questions

When is the last frost in Platteville?

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

When is the first frost in Platteville?

The first fall frost (32°F) usually arrives around October 13. There’s a 10% chance of a freeze by September 29 and a 90% chance by October 24.

Can it frost in Platteville 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 8.

What growing zone is Platteville?

Platteville is in USDA Plant Hardiness Zone 5a (average annual extreme minimum temperature −20 to −15°F), based on the 2023 USDA map for ZIP code 53818. See growing zones in Wisconsin.

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