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Will it freeze in Byron in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Tonight: 30°F (Thu, Nov 5, 6:00 PM CST to Fri, Nov 6, 6:00 AM CST).
Tonight: forecast low 30°F. Freeze.
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 30°F Freeze · Mostly Cloudy
- Fri, Nov 6 26°F Hard freeze · Partly Cloudy
- Sat, Nov 7 35°F Frost possible · Partly Cloudy
- Sun, Nov 8 37°F Above 36°F · Mostly Clear
- Mon, Nov 9 39°F Above 36°F · Mostly Clear
- Tue, Nov 10 36°F Frost possible · Mostly 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 Byron
The median first fall hard-freeze date (28°F) is October 5, from NOAA’s 1991–2020 Climate Normals at Byron 4NORTH. 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 | May 8 · May 22 · Jun 4 | Sep 5 · Sep 19 · Oct 2 | 120 days |
| 32°F freeze | Apr 29 · May 12 · May 25 | Sep 14 · Sep 28 · Oct 10 | 139 days |
| 28°F hard freeze | Apr 18 · May 2 · May 15 | Sep 22 · Oct 5 · Oct 18 | 156 days |
Average high temperature by month
1991–2020 normals at Byron 4NORTH
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 Byron, MN come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Byron 4NORTH (station USC00211174, elevation 1,041 ft), 3.6 mi from Byron. 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 Byron
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Kasson, MN | 5.6 mi | May 12 | Sep 28 |
| Rochester, MN | 8.1 mi | Apr 30 | Oct 6 |
| Stewartville, MN | 14 mi | Apr 30 | Oct 6 |
| Owatonna, MN | 30 mi | May 5 | Oct 6 |
| Austin, MN | 30 mi | Apr 30 | Oct 5 |
| Lake City, MN | 34 mi | May 7 | Oct 2 |
| Faribault, MN | 37 mi | May 5 | Oct 5 |
| Red Wing, MN | 37 mi | Apr 23 | Oct 14 |
| Northfield, MN | 39 mi | May 5 | Oct 5 |
| Waseca, MN | 43 mi | May 2 | Oct 4 |
Frequently asked questions
When is the last frost in Byron?
On average, the last spring frost (32°F) in Byron is around May 12. In about 1 year in 10 it comes after May 25, and in 9 years in 10 it comes after April 29.
When is the first frost in Byron?
The first fall frost (32°F) usually arrives around September 28. There’s a 10% chance of a freeze by September 14 and a 90% chance by October 10.
Can it frost in Byron 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 22.
What growing zone is Byron?
Byron 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 55920. See growing zones in Minnesota.
More: all Minnesota frost dates · Minnesota growing zones · frost vs. freeze