Frost dates for Sault Ste Marie, MI
At Sault Ste Marie, the median last spring frost (32°F) is May 22 and the median first fall frost is Oct 4, for a typical growing season of 136 days. For a 90% chance that the last frost has passed, wait until Jun 4. Nearby ZIP codes are in USDA hardiness zones 4b to 5a.
- May 22Last spring frost (median)50% chance of 32°F after this date
- Jun 4Safer planting date10% chance of 32°F after this date
- Oct 4First fall frost (median)50% chance of 32°F by this date
- 136 daysGrowing season (median)between 32°F freezes
Last spring frost dates
The chance that the temperature drops to the threshold after each date.
| Temperature | 90% chance later | 50% chance later | 10% chance later |
|---|---|---|---|
| 36°F | May 22 | Jun 2 | Jun 18 |
| 32°F | May 5 | May 22 | Jun 4 |
| 28°F | Apr 24 | May 7 | May 22 |
| 24°F | Apr 11 | Apr 24 | May 7 |
First fall frost dates
The chance that the temperature has dropped to the threshold by each date.
| Temperature | 10% chance by | 50% chance by | 90% chance by |
|---|---|---|---|
| 36°F | Sep 8 | Sep 25 | Oct 5 |
| 32°F | Sep 22 | Oct 4 | Oct 18 |
| 28°F | Oct 3 | Oct 17 | Nov 1 |
| 24°F | Oct 19 | Nov 1 | Nov 16 |
Growing season length
Days between the last spring and first fall freeze, as the length reached in 9, 5 and 1 out of 10 years.
| Temperature | 9 in 10 years at least | 5 in 10 years at least | 1 in 10 years at least |
|---|---|---|---|
| 36°F | 92 days | 112 days | 132 days |
| 32°F | 117 days | 136 days | 159 days |
| 28°F | 143 days | 164 days | 184 days |
| 24°F | 170 days | 190 days | 210 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
Closest ZIP codes (each is closer to another station)
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 49783 | 4b | -25 to -20°F | 12 km |
| 49724 | 4b | -25 to -20°F | 18 km |
| 49715 | 4b | -25 to -20°F | 24 km |
| 49752 | 4b | -25 to -20°F | 25 km |
| 49788 | 5a | -20 to -15°F | 25 km |
| 49784 | 5a | -20 to -15°F | 26 km |
| 49710 | 4b | -25 to -20°F | 29 km |
| 49774 | 4b | -25 to -20°F | 37 km |
Not the official USDA Plant Hardiness Zone Map. Zones shown here are the values published in the USDA-ARS / Oregon State University PRISM Group 2023 ZIP code tables, shown unaltered. For the official interactive map, visit planthardiness.ars.usda.gov.
About this station
- NOAA station ID USC00207364, at 46.4867, -84.4089, elevation 192 m (630 ft).
- Data quality: Representative (10+ years), 20 years of freeze data.
- Average days per year at or below 32°F: 179.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Sault Ste Marie Sanderson Field (4 km)
- Rudyard 4n (25 km)
- Rudyard 5se (34 km)
- Pickford 3ne (34 km)
- Paradise (50 km)
- Whitefish Point (53 km)
- Trout Lake 1sw (59 km)
- Tahquamenon Falls State Park (64 km)
Sources
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, annual/seasonal normals by station (version 1.0.1), file dated June 27, 2023; documentation.
- USDA Agricultural Research Service and PRISM Group, Oregon State University, 2023 Plant Hardiness Zone Map ZIP code tables (CONUS, Alaska, Hawaii, Puerto Rico), files dated November 17, 2023. Data © PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed November 1, 2026. Official map: planthardiness.ars.usda.gov.
- U.S. Census Bureau, 2024 Gazetteer ZIP Code Tabulation Areas file, dated August 30, 2024 (ZIP centroids used to find the nearest station).
Freeze dates are 30-year probabilities, not forecasts. Check your local forecast before planting tender plants.