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Will it freeze in Greendale in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Fri, Nov 6: 30°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 30°F Freeze · Partly Cloudy
- 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 39°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 Greendale
The median first fall hard-freeze date (28°F) is October 24, from NOAA’s 1991–2020 Climate Normals at Hales Corners/whitnall Park/bo. 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 30 · May 14 · May 29 | Sep 22 · Oct 3 · Oct 15 | 141 days |
| 32°F freeze | Apr 18 · May 3 · May 19 | Sep 30 · Oct 14 · Oct 26 | 162 days |
| 28°F hard freeze | Apr 8 · Apr 21 · May 9 | Oct 8 · Oct 24 · Nov 6 | 183 days |
Average high temperature by month
1991–2020 normals at Hales Corners/whitnall Park/bo
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 Greendale, WI come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Hales Corners/whitnall Park/bo (station USC00473391, elevation 774 ft), 1.5 mi from Greendale. 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 Greendale
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Greenfield, WI | 1.2 mi | May 3 | Oct 14 |
| Hales Corners, WI | 2.5 mi | May 3 | Oct 14 |
| Franklin, WI | 3.7 mi | May 3 | Oct 14 |
| West Allis, WI | 5.0 mi | Apr 26 | Oct 22 |
| Oak Creek, WI | 6.8 mi | Apr 22 | Oct 26 |
| New Berlin, WI | 6.8 mi | May 3 | Oct 14 |
| St. Francis, WI | 6.8 mi | Apr 19 | Oct 29 |
| Cudahy, WI | 6.8 mi | Apr 19 | Oct 29 |
| South Milwaukee, WI | 7.5 mi | Apr 22 | Oct 26 |
| Muskego, WI | 8.1 mi | May 3 | Oct 14 |
Frequently asked questions
When is the last frost in Greendale?
On average, the last spring frost (32°F) in Greendale is around May 3. In about 1 year in 10 it comes after May 19, and in 9 years in 10 it comes after April 18.
When is the first frost in Greendale?
The first fall frost (32°F) usually arrives around October 14. There’s a 10% chance of a freeze by September 30 and a 90% chance by October 26.
Can it frost in Greendale 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 14.
What growing zone is Greendale?
Greendale 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 53129. See growing zones in Wisconsin.
More: all Wisconsin frost dates · Wisconsin growing zones · frost vs. freeze