Frost dates 2026–2027

Frost dates for Germantown, Wisconsin

Median (50% chance) dates of the last and first 32°F frost, from NOAA 1991–2020 climate normals at Germantown, 0.3 mi away (close match).

Last spring frostMay 6
First fall frostOct 8
154 frost-free days
Last spring frostMay 61 year in 10 after May 25
First fall frostOct 81 year in 10 by Sep 26
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 Germantown in the next 7 nights?

The earliest overnight low at or below 32°F in the available NWS frost forecast is Fri, Nov 6: 28°F (Fri, Nov 6, 6:00 PM CST to Sat, Nov 7, 6:00 AM CST).

Tonight: forecast low 36°F. Frost possible.

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

5 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 Germantown

The median first fall hard-freeze date (28°F) is October 20, from NOAA’s 1991–2020 Climate Normals at Germantown. 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 2 · May 19 · Jun 3 Sep 13 · Sep 29 · Oct 11 132 days
32°F freeze Apr 22 · May 6 · May 25 Sep 26 · Oct 8 · Oct 24 154 days
28°F hard freeze Apr 9 · Apr 24 · May 12 Oct 4 · Oct 20 · Nov 3 178 days
NOAA NCEI U.S. Climate Normals 1991–2020, station USC00473058. How to read these probabilities.

Average high temperature by month

1991–2020 normals at Germantown

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 Germantown, WI come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Germantown (station USC00473058, elevation 850 ft), 0.3 mi from Germantown. 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 Germantown

CityDistanceLast spring frostFirst fall frost
Menomonee Falls, WI 5.0 mi May 6 Oct 8
Richfield, WI 5.6 mi Apr 30 Oct 16
Mequon, WI 5.6 mi May 6 Oct 8
Jackson, WI 6.2 mi Apr 30 Oct 15
Cedarburg, WI 8.1 mi Apr 23 Oct 24
Lisbon, WI 8.1 mi Apr 30 Oct 16
Sussex, WI 8.7 mi Apr 30 Oct 16
Brown Deer, WI 8.7 mi Apr 26 Oct 18
Slinger, WI 11 mi May 5 Oct 5
Grafton, WI 11 mi Apr 23 Oct 24

Frequently asked questions

When is the last frost in Germantown?

On average, the last spring frost (32°F) in Germantown is around May 6. In about 1 year in 10 it comes after May 25, and in 9 years in 10 it comes after April 22.

When is the first frost in Germantown?

The first fall frost (32°F) usually arrives around October 8. There’s a 10% chance of a freeze by September 26 and a 90% chance by October 24.

Can it frost in Germantown 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 Germantown?

Germantown 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 53022. See growing zones in Wisconsin.

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