Frost dates 2026–2027

Frost dates for Suamico, Wisconsin

Median (50% chance) dates of the last and first 32°F frost, from NOAA 1991–2020 climate normals at Green Bay Botanical, 7.2 mi away (close match).

Last spring frostMay 7
First fall frostOct 9
154 frost-free days
Last spring frostMay 71 year in 10 after May 22
First fall frostOct 91 year in 10 by Sep 23
Growing season154 daysbetween median 32°F dates
Hardiness zoneZone 5b−15 to −10°F average extreme low

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Will it freeze in Suamico 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 35°F. Frost possible.

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

6 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 Suamico

The median first fall hard-freeze date (28°F) is October 25, from NOAA’s 1991–2020 Climate Normals at Green Bay Botanical. 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 May 4 · May 19 · May 31 Sep 15 · Sep 28 · Oct 12 132 days
32°F freeze Apr 24 · May 7 · May 22 Sep 23 · Oct 9 · Oct 25 154 days
28°F hard freeze Apr 10 · Apr 27 · May 12 Oct 5 · Oct 25 · Nov 7 180 days
NOAA NCEI U.S. Climate Normals 1991–2020, station USC00473271. How to read these probabilities.

Average high temperature by month

1991–2020 normals at Green Bay Botanical

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 Suamico, WI come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Green Bay Botanical (station USC00473271, elevation 694 ft), 7.2 mi from Suamico. 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 Suamico

CityDistanceLast spring frostFirst fall frost
Howard, WI 4.3 mi May 7 Oct 9
Green Bay, WI 7.5 mi May 7 Oct 9
Ashwaubenon, WI 11 mi Apr 30 Oct 9
Allouez, WI 11 mi Apr 30 Oct 9
Hobart, WI 11 mi May 1 Oct 11
Bellevue, WI 12 mi Apr 30 Oct 9
De Pere, WI 14 mi Apr 30 Oct 9
Kaukauna, WI 27 mi May 4 Oct 6
Little Chute, WI 27 mi May 4 Oct 6
Shawano, WI 29 mi May 9 Oct 2

Frequently asked questions

When is the last frost in Suamico?

On average, the last spring frost (32°F) in Suamico is around May 7. In about 1 year in 10 it comes after May 22, and in 9 years in 10 it comes after April 24.

When is the first frost in Suamico?

The first fall frost (32°F) usually arrives around October 9. There’s a 10% chance of a freeze by September 23 and a 90% chance by October 25.

Can it frost in Suamico 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 19.

What growing zone is Suamico?

Suamico 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 54173. See growing zones in Wisconsin.

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