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Will it freeze in Waukesha in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Fri, Nov 6: 29°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.
- Tonight 35°F Frost possible · Mostly Cloudy
- Fri, Nov 6 29°F Freeze · Mostly Clear
- Sat, Nov 7 32°F Freeze · Partly Cloudy
- Sun, Nov 8 34°F Frost possible · Mostly Clear
- Mon, Nov 9 40°F Above 36°F · Mostly Clear
- Tue, Nov 10 37°F Above 36°F · Partly Cloudy
- Wed, Nov 11 37°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 Waukesha
The median first fall hard-freeze date (28°F) is October 23, from NOAA’s 1991–2020 Climate Normals at Waukesha 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 | Apr 29 · May 13 · May 29 | Sep 20 · Oct 2 · Oct 15 | 141 days |
| 32°F freeze | Apr 18 · May 1 · May 18 | Sep 29 · Oct 13 · Oct 25 | 162 days |
| 28°F hard freeze | Apr 6 · Apr 19 · May 5 | Oct 8 · Oct 23 · Nov 6 | 185 days |
Average high temperature by month
1991–2020 normals at Waukesha 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 Waukesha, WI come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Waukesha Wastewater Plant (station USC00478937, elevation 789 ft), 0.2 mi from Waukesha. 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 Waukesha
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Waukesha, WI | 3.1 mi | May 1 | Oct 13 |
| Pewaukee, WI | 3.7 mi | Apr 30 | Oct 14 |
| Pewaukee, WI | 5.6 mi | Apr 30 | Oct 14 |
| New Berlin, WI | 6.2 mi | May 3 | Oct 14 |
| Brookfield, WI | 7.5 mi | Apr 30 | Oct 14 |
| Hartland, WI | 8.1 mi | May 1 | Oct 13 |
| Delafield, WI | 8.1 mi | Apr 30 | Oct 12 |
| Elm Grove, WI | 8.7 mi | Apr 26 | Oct 18 |
| Sussex, WI | 8.7 mi | Apr 30 | Oct 16 |
| Vernon, WI | 9.3 mi | May 1 | Oct 13 |
Frequently asked questions
When is the last frost in Waukesha?
On average, the last spring frost (32°F) in Waukesha is around May 1. In about 1 year in 10 it comes after May 18, and in 9 years in 10 it comes after April 18.
When is the first frost in Waukesha?
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 25.
Can it frost in Waukesha 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 13.
What growing zone is Waukesha?
Waukesha 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 53186. See growing zones in Wisconsin.
More: all Wisconsin frost dates · Wisconsin growing zones · UV index today in Waukesha · frost vs. freeze