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Will it freeze in South Lyon in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Sat, Nov 7: 30°F (Sat, Nov 7, 6:00 PM EST to Sun, Nov 8, 6:00 AM EST).
Tonight: forecast low 38°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 38°F Above 36°F · Light Rain Likely
- Fri, Nov 6 33°F Frost possible · Chance Light Rain
- Sat, Nov 7 30°F Freeze · Partly Cloudy
- Sun, Nov 8 32°F Freeze · Mostly Clear
- Mon, Nov 9 39°F Above 36°F · Mostly Clear
- Tue, Nov 10 34°F Frost possible · Mostly Clear
- Wed, Nov 11 33°F Frost possible · Mostly 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 South Lyon
The median first fall hard-freeze date (28°F) is October 26, from NOAA’s 1991–2020 Climate Normals at Whitmore Lake 1NW. 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 1 · May 17 · May 31 | Sep 20 · Oct 1 · Oct 13 | 139 days |
| 32°F freeze | Apr 22 · May 5 · May 21 | Sep 30 · Oct 13 · Oct 26 | 160 days |
| 28°F hard freeze | Apr 12 · Apr 26 · May 10 | Oct 12 · Oct 26 · Nov 7 | 184 days |
Average high temperature by month
1991–2020 normals at Whitmore Lake 1NW
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 South Lyon, MI come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Whitmore Lake 1NW (station USC00208972, elevation 906 ft), 6.8 mi from South Lyon. 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 South Lyon
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Wixom, MI | 7.5 mi | May 6 | Oct 12 |
| Brighton, MI | 8.1 mi | May 6 | Oct 12 |
| Novi, MI | 8.7 mi | May 1 | Oct 17 |
| Northville, MI | 8.7 mi | May 1 | Oct 17 |
| Milford, MI | 9.3 mi | May 6 | Oct 12 |
| Walled Lake, MI | 11 mi | May 1 | Oct 17 |
| Plymouth, MI | 11 mi | May 1 | Oct 17 |
| Ann Arbor, MI | 14 mi | May 5 | Oct 10 |
| Farmington, MI | 14 mi | May 1 | Oct 17 |
| Farmington Hills, MI | 14 mi | May 1 | Oct 17 |
Frequently asked questions
When is the last frost in South Lyon?
On average, the last spring frost (32°F) in South Lyon is around May 5. In about 1 year in 10 it comes after May 21, and in 9 years in 10 it comes after April 22.
When is the first frost in South Lyon?
The first fall frost (32°F) usually arrives around October 13. There’s a 10% chance of a freeze by September 30 and a 90% chance by October 26.
Can it frost in South Lyon 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 17.
What growing zone is South Lyon?
South Lyon 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 48178. See growing zones in Michigan.
More: all Michigan frost dates · Michigan growing zones · frost vs. freeze