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Will it freeze in Watertown in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Fri, Nov 6: 26°F (Fri, Nov 6, 6:00 PM CST to Sat, Nov 7, 6:00 AM CST).
Tonight: forecast low 34°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 34°F Frost possible · Mostly Cloudy
- Fri, Nov 6 26°F Hard freeze · Mostly Clear
- Sat, Nov 7 31°F Freeze · Partly Cloudy
- Sun, Nov 8 32°F Freeze · Clear
- Mon, Nov 9 38°F Above 36°F · Mostly Clear
- Tue, Nov 10 35°F Frost possible · Partly Cloudy
- Wed, Nov 11 35°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 Watertown
The median first fall hard-freeze date (28°F) is October 25, from NOAA’s 1991–2020 Climate Normals at Watertown 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 25 · May 9 · May 24 | Sep 20 · Oct 2 · Oct 15 | 145 days |
| 32°F freeze | Apr 14 · Apr 28 · May 13 | Sep 28 · Oct 12 · Oct 27 | 167 days |
| 28°F hard freeze | Apr 3 · Apr 16 · Apr 30 | Oct 8 · Oct 25 · Nov 6 | 191 days |
Average high temperature by month
1991–2020 normals at Watertown 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 Watertown, WI come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Watertown Wastewater Plant (station USC00478919, elevation 825 ft), 1.1 mi from Watertown. 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 Watertown
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Lake Mills, WI | 12 mi | Apr 29 | Oct 14 |
| Oconomowoc, WI | 13 mi | Apr 30 | Oct 12 |
| Jefferson, WI | 14 mi | Apr 25 | Oct 18 |
| Summit, WI | 16 mi | Apr 30 | Oct 12 |
| Columbus, WI | 18 mi | Apr 30 | Oct 9 |
| Delafield, WI | 19 mi | Apr 30 | Oct 12 |
| Fort Atkinson, WI | 19 mi | Apr 28 | Oct 13 |
| Hartford, WI | 20 mi | May 8 | Oct 3 |
| Beaver Dam, WI | 21 mi | May 2 | Oct 9 |
| Hartland, WI | 21 mi | May 1 | Oct 13 |
Frequently asked questions
When is the last frost in Watertown?
On average, the last spring frost (32°F) in Watertown is around April 28. In about 1 year in 10 it comes after May 13, and in 9 years in 10 it comes after April 14.
When is the first frost in Watertown?
The first fall frost (32°F) usually arrives around October 12. There’s a 10% chance of a freeze by September 28 and a 90% chance by October 27.
Can it frost in Watertown 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 9.
What growing zone is Watertown?
Watertown 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 53094. See growing zones in Wisconsin.
More: all Wisconsin frost dates · Wisconsin growing zones · frost vs. freeze