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Will it freeze in Mukwonago 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 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.
- Tonight 35°F Frost possible · Mostly Cloudy
- Fri, Nov 6 28°F Hard freeze · Mostly Clear
- Sat, Nov 7 32°F Freeze · Mostly Clear
- Sun, Nov 8 33°F Frost possible · Mostly Clear
- Mon, Nov 9 39°F Above 36°F · Mostly Clear
- Tue, Nov 10 36°F Frost possible · Partly Cloudy
- Wed, Nov 11 36°F Frost possible · 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 Mukwonago
The median first fall hard-freeze date (28°F) is October 21, from NOAA’s 1991–2020 Climate Normals at Rochester 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 3 · May 19 · Jun 2 | Sep 19 · Oct 1 · Oct 13 | 134 days |
| 32°F freeze | Apr 23 · May 5 · May 23 | Sep 26 · Oct 10 · Oct 22 | 156 days |
| 28°F hard freeze | Apr 8 · Apr 24 · May 10 | Oct 6 · Oct 21 · Nov 3 | 179 days |
Average high temperature by month
1991–2020 normals at Rochester 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 Mukwonago, WI come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Rochester Wastewater Plant (station USC00477314, elevation 783 ft), 9.9 mi from Mukwonago. 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 Mukwonago
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Vernon, WI | 3.1 mi | May 1 | Oct 13 |
| Waterford, WI | 8.1 mi | May 5 | Oct 10 |
| Waukesha, WI | 8.1 mi | May 1 | Oct 13 |
| Muskego, WI | 9.3 mi | May 3 | Oct 14 |
| Waukesha, WI | 11 mi | May 1 | Oct 13 |
| Burlington, WI | 12 mi | May 5 | Oct 9 |
| New Berlin, WI | 12 mi | May 3 | Oct 14 |
| Hales Corners, WI | 15 mi | May 3 | Oct 14 |
| Delafield, WI | 15 mi | Apr 30 | Oct 12 |
| Pewaukee, WI | 15 mi | Apr 30 | Oct 14 |
Frequently asked questions
When is the last frost in Mukwonago?
On average, the last spring frost (32°F) in Mukwonago is around May 5. In about 1 year in 10 it comes after May 23, and in 9 years in 10 it comes after April 23.
When is the first frost in Mukwonago?
The first fall frost (32°F) usually arrives around October 10. There’s a 10% chance of a freeze by September 26 and a 90% chance by October 22.
Can it frost in Mukwonago 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 Mukwonago?
Mukwonago 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 53149. See growing zones in Wisconsin.
More: all Wisconsin frost dates · Wisconsin growing zones · frost vs. freeze