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Will it freeze in Mahtomedi in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Fri, Nov 6: 29°F (Fri, Nov 6, 6:00 PM CST to Sat, Nov 7, 6:00 AM CST).
Tonight: forecast low 33°F. Frost possible.
NWS forecast period: Thu, Nov 5, 6:00 PM CST to Fri, Nov 6, 6:00 AM CST.
2 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.
- Tonight 33°F Frost possible · Mostly Cloudy
- Fri, Nov 6 29°F Freeze · Partly Cloudy
- Sat, Nov 7 37°F Above 36°F · Mostly Clear
- Sun, Nov 8 39°F Above 36°F · Mostly Clear
- Mon, Nov 9 40°F Above 36°F · Mostly Clear
- Tue, Nov 10 37°F Above 36°F · Partly Cloudy
- Wed, Nov 11 38°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 Mahtomedi
The median first fall hard-freeze date (28°F) is October 23, from NOAA’s 1991–2020 Climate Normals at Stillwater 2SW. 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 26 · May 8 · May 23 | Sep 20 · Oct 2 · Oct 14 | 145 days |
| 32°F freeze | Apr 17 · Apr 30 · May 13 | Sep 28 · Oct 11 · Oct 23 | 163 days |
| 28°F hard freeze | Apr 6 · Apr 20 · May 2 | Oct 10 · Oct 23 · Nov 4 | 184 days |
Average high temperature by month
1991–2020 normals at Stillwater 2SW
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 Mahtomedi, MN come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Stillwater 2SW (station USC00218039, elevation 898 ft), 5.8 mi from Mahtomedi. 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 Mahtomedi
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| White Bear Lake, MN | 1.9 mi | Apr 23 | Oct 20 |
| North St. Paul, MN | 3.7 mi | Apr 26 | Oct 12 |
| Maplewood, MN | 3.7 mi | Apr 23 | Oct 20 |
| Vadnais Heights, MN | 5.0 mi | Apr 23 | Oct 20 |
| Oakdale, MN | 5.0 mi | Apr 26 | Oct 12 |
| Lake Elmo, MN | 5.6 mi | Apr 30 | Oct 11 |
| Little Canada, MN | 6.2 mi | Apr 23 | Oct 20 |
| Stillwater, MN | 6.8 mi | Apr 30 | Oct 11 |
| North Oaks, MN | 7.5 mi | Apr 23 | Oct 20 |
| Hugo, MN | 7.5 mi | Apr 30 | Oct 11 |
Frequently asked questions
When is the last frost in Mahtomedi?
On average, the last spring frost (32°F) in Mahtomedi is around April 30. In about 1 year in 10 it comes after May 13, and in 9 years in 10 it comes after April 17.
When is the first frost in Mahtomedi?
The first fall frost (32°F) usually arrives around October 11. There’s a 10% chance of a freeze by September 28 and a 90% chance by October 23.
Can it frost in Mahtomedi 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 Mahtomedi?
Mahtomedi is in USDA Plant Hardiness Zone 5a (average annual extreme minimum temperature −20 to −15°F), based on the 2023 USDA map for ZIP code 55115. See growing zones in Minnesota.
More: all Minnesota frost dates · Minnesota growing zones · frost vs. freeze