When to plant in Sault Ste. Marie, MI
USDA Zone 4bSault Ste. Marie, Michigan frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
Zone 4b is cold — in Sault Ste. Marie, most perennials must be fully hardy, and your frost dates set a tight window for tender annual vegetables.
The average last spring frost in Sault Ste. Marie is now 6 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
SAULT STE MARIE SANDERSON FLD · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Sault Ste. Marie’s own odds, recorded at SAULT STE MARIE SANDERSON FLD.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Jun 11 | May 26 | May 10 | Sep 15 | Sep 29 | Oct 12 |
| 32°F | May 27 | May 9 | Apr 27 | Sep 26 | Oct 11 | Oct 26 |
| 28°F | May 10 | Apr 27 | Apr 14 | Oct 8 | Oct 26 | Nov 9 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Sault Ste. Marie, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 25 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Sault Ste. Marie planting FAQ
When is the last spring frost in Sault Ste. Marie, MI?
Sault Ste. Marie's average last spring frost falls near May 9 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Sault Ste. Marie, MI?
Expect Sault Ste. Marie's first fall frost near October 11 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Sault Ste. Marie in?
Sault Ste. Marie is in USDA hardiness zone 4b. In zone 4b, winters are cold — pick cold-hardy varieties and protect tender crops.
How long is the growing season in Sault Ste. Marie?
There are roughly 155 frost-free days in Sault Ste. Marie (a moderate growing season), running from the average last frost around May 9 to the first fall frost near October 11.
When should I plant tomatoes in Sault Ste. Marie?
In Sault Ste. Marie, start tomato seeds indoors around March 14–March 28, then transplant seedlings outdoors around May 16 once the danger of frost has passed.
Never miss a window in Sault Ste. Marie
An email when it’s time to start seeds, transplant, and sow — timed to Sault Ste. Marie’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Alpena · 172 km
- Traverse City · 214 km
- Escanaba · 224 km
- Marquette · 232 km
- Cadillac · 261 km
- Marinette · 296 km
- Midland · 317 km
- Mount Pleasant · 322 km
Frost dates recorded at SAULT STE MARIE SANDERSON FLD, 1 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Sault Ste. Marie, MI — Frost Dates & Zone 4b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00014847. Retrieved from https://blissgarden.com/michigan/sault-ste-marie.