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Will it freeze in Altoona in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Tonight: 32°F (Thu, Nov 5, 6:00 PM CST to Fri, Nov 6, 6:00 AM CST).
Tonight: forecast low 32°F. Freeze.
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 32°F Freeze · Mostly Cloudy
- Fri, Nov 6 25°F Hard freeze · Partly Cloudy then Areas Of Fog
- Sat, Nov 7 33°F Frost possible · Partly Cloudy
- Sun, Nov 8 34°F Frost possible · Mostly Clear
- Mon, Nov 9 37°F Above 36°F · Mostly Clear
- Tue, Nov 10 35°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 Altoona
The median first fall hard-freeze date (28°F) is October 26, from NOAA’s 1991–2020 Climate Normals at Eau Claire 3SW. 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 20 · May 5 · May 17 | Sep 19 · Oct 3 · Oct 17 | 150 days |
| 32°F freeze | Apr 9 · Apr 24 · May 7 | Sep 26 · Oct 14 · Oct 28 | 170 days |
| 28°F hard freeze | Apr 1 · Apr 14 · Apr 30 | Oct 10 · Oct 26 · Nov 7 | 192 days |
Average high temperature by month
1991–2020 normals at Eau Claire 3SW
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 Altoona, WI come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Eau Claire 3SW (station USC00472425, elevation 880 ft), 3.9 mi from Altoona. 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 Altoona
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Eau Claire, WI | 3.1 mi | Apr 24 | Oct 14 |
| Lake Hallie, WI | 6.2 mi | May 8 | Oct 4 |
| Chippewa Falls, WI | 9.3 mi | May 8 | Oct 4 |
| Menomonie, WI | 24 mi | May 9 | Oct 1 |
| Lake City, MN | 48 mi | May 7 | Oct 2 |
| Rice Lake, WI | 50 mi | May 8 | Oct 2 |
| Winona, MN | 53 mi | Apr 21 | Oct 19 |
| Holmen, WI | 58 mi | Apr 23 | Oct 17 |
| River Falls, WI | 58 mi | May 11 | Oct 1 |
| New Richmond, WI | 58 mi | Apr 22 | Oct 19 |
Frequently asked questions
When is the last frost in Altoona?
On average, the last spring frost (32°F) in Altoona is around April 24. In about 1 year in 10 it comes after May 7, and in 9 years in 10 it comes after April 9.
When is the first frost in Altoona?
The first fall frost (32°F) usually arrives around October 14. There’s a 10% chance of a freeze by September 26 and a 90% chance by October 28.
Can it frost in Altoona 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 5.
What growing zone is Altoona?
Altoona is in USDA Plant Hardiness Zone 4b (average annual extreme minimum temperature −25 to −20°F), based on the 2023 USDA map for ZIP code 54720. See growing zones in Wisconsin.
More: all Wisconsin frost dates · Wisconsin growing zones · frost vs. freeze