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Will it freeze in Plymouth 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.
4 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.
- Tonight 36°F Frost possible · Mostly Cloudy
- Fri, Nov 6 28°F Hard freeze · Mostly Clear
- Sat, Nov 7 33°F Frost possible · Partly Cloudy
- Sun, Nov 8 35°F Frost possible · Mostly Clear
- Mon, Nov 9 41°F Above 36°F · Mostly Clear
- Tue, Nov 10 37°F Above 36°F · Partly Cloudy
- Wed, Nov 11 38°F Above 36°F · Partly Cloudy
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 Plymouth
The median first fall hard-freeze date (28°F) is October 23, from NOAA’s 1991–2020 Climate Normals at Plymouth Wastewater Plant. This is the 50% probability date, not a forecast for this year.
| Temperature | Last 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 1 · May 18 · Jun 1 | Sep 18 · Sep 30 · Oct 13 | 135 days |
| 32°F freeze | Apr 19 · May 3 · May 20 | Sep 28 · Oct 10 · Oct 25 | 159 days |
| 28°F hard freeze | Apr 6 · Apr 20 · May 5 | Oct 6 · Oct 23 · Nov 6 | 183 days |
Average high temperature by month
1991–2020 normals at Plymouth Wastewater Plant
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 Plymouth, WI come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Plymouth Wastewater Plant (station USC00476678, elevation 828 ft), 1.1 mi from Plymouth. 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 Plymouth
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Sheboygan Falls, WI | 6.8 mi | May 5 | Oct 8 |
| Sheboygan, WI | 12 mi | Apr 25 | Oct 23 |
| Fond du Lac, WI | 24 mi | Apr 27 | Oct 19 |
| West Bend, WI | 25 mi | May 1 | Oct 12 |
| Port Washington, WI | 25 mi | Apr 27 | Oct 22 |
| North Fond du Lac, WI | 26 mi | May 1 | Oct 12 |
| Manitowoc, WI | 28 mi | Apr 30 | Oct 20 |
| Grafton, WI | 29 mi | Apr 23 | Oct 24 |
| Cedarburg, WI | 31 mi | Apr 23 | Oct 24 |
| Jackson, WI | 31 mi | Apr 30 | Oct 15 |
Frequently asked questions
When is the last frost in Plymouth?
On average, the last spring frost (32°F) in Plymouth is around May 3. In about 1 year in 10 it comes after May 20, and in 9 years in 10 it comes after April 19.
When is the first frost in Plymouth?
The first fall frost (32°F) usually arrives around October 10. There’s a 10% chance of a freeze by September 28 and a 90% chance by October 25.
Can it frost in Plymouth 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 18.
What growing zone is Plymouth?
Plymouth 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 53073. See growing zones in Wisconsin.
More: all Wisconsin frost dates · Wisconsin growing zones · frost vs. freeze