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Will it freeze in Portage in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Fri, Nov 6: 32°F (Fri, Nov 6, 6:00 PM EST to Sat, Nov 7, 6:00 AM EST).
Tonight: forecast low 37°F. Above 36°F.
NWS forecast period: Thu, Nov 5, 6:00 PM EST to Fri, Nov 6, 6:00 AM EST.
5 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.
- Tonight 37°F Above 36°F · Rain Showers Likely
- Fri, Nov 6 32°F Freeze · Partly Cloudy
- Sat, Nov 7 31°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 35°F Frost possible · Mostly Clear
- 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 Portage
The median first fall hard-freeze date (28°F) is November 1, from NOAA’s 1991–2020 Climate Normals at Kalamazoo Battle Ck Intl Airport. 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 24 · May 8 · May 24 | Sep 22 · Oct 6 · Oct 19 | 149 days |
| 32°F freeze | Apr 13 · Apr 28 · May 13 | Oct 2 · Oct 18 · Nov 1 | 172 days |
| 28°F hard freeze | Apr 3 · Apr 17 · May 3 | Oct 16 · Nov 1 · Nov 14 | 196 days |
Average high temperature by month
1991–2020 normals at Kalamazoo Battle Ck Intl Airport
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 Portage, MI come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Kalamazoo Battle Ck Intl Airport (station USW00094815, elevation 868 ft), 3.3 mi from Portage. 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 Portage
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Kalamazoo, MI | 5.6 mi | Apr 28 | Oct 18 |
| Three Rivers, MI | 17 mi | Apr 30 | Oct 17 |
| Battle Creek, MI | 20 mi | Apr 30 | Oct 19 |
| Springfield, MI | 21 mi | Apr 30 | Oct 19 |
| Allegan, MI | 26 mi | May 4 | Oct 15 |
| Sturgis, MI | 29 mi | Apr 26 | Oct 21 |
| Dowagiac, MI | 30 mi | May 4 | Oct 11 |
| Marshall, MI | 32 mi | Apr 30 | Oct 19 |
| Hastings, MI | 35 mi | May 3 | Oct 12 |
| Coldwater, MI | 35 mi | May 2 | Oct 13 |
Frequently asked questions
When is the last frost in Portage?
On average, the last spring frost (32°F) in Portage 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 13.
When is the first frost in Portage?
The first fall frost (32°F) usually arrives around October 18. There’s a 10% chance of a freeze by October 2 and a 90% chance by November 1.
Can it frost in Portage 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 8.
What growing zone is Portage?
Portage is in USDA Plant Hardiness Zone 6a (average annual extreme minimum temperature −10 to −5°F), based on the 2023 USDA map for ZIP code 49024. See growing zones in Michigan.
More: all Michigan frost dates · Michigan growing zones · UV index today in Portage · frost vs. freeze