Frost dates for Ionia 2ssw, MI
At Ionia 2ssw, the median last spring frost (32°F) is May 3 and the median first fall frost is Oct 12, for a typical growing season of 161 days. For a 90% chance that the last frost has passed, wait until May 21. Nearby ZIP codes are in USDA hardiness zone 6a.
- May 3Last spring frost (median)50% chance of 32°F after this date
- May 21Safer planting date10% chance of 32°F after this date
- Oct 12First fall frost (median)50% chance of 32°F by this date
- 161 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 | Apr 30 | May 16 | Jun 1 |
| 32°F | Apr 17 | May 3 | May 21 |
| 28°F | Apr 7 | Apr 22 | May 9 |
| 24°F | Mar 28 | Apr 10 | Apr 25 |
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 18 | Oct 1 | Oct 15 |
| 32°F | Sep 29 | Oct 12 | Oct 27 |
| 28°F | Oct 7 | Oct 27 | Nov 10 |
| 24°F | Oct 25 | Nov 8 | Nov 26 |
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 | 119 days | 139 days | 159 days |
| 32°F | 139 days | 161 days | 183 days |
| 28°F | 162 days | 186 days | 207 days |
| 24°F | 191 days | 212 days | 235 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 48846 | 6a | -10 to -5°F | 4 km |
| 48881 | 6a | -10 to -5°F | 11 km |
| 48851 | 6a | -10 to -5°F | 12 km |
| 48875 | 6a | -10 to -5°F | 15 km |
| 48865 | 6a | -10 to -5°F | 15 km |
| 48860 | 6a | -10 to -5°F | 17 km |
| 48849 | 6a | -10 to -5°F | 18 km |
| 48870 | 6a | -10 to -5°F | 19 km |
| 48815 | 6a | -10 to -5°F | 20 km |
| 48873 | 6a | -10 to -5°F | 21 km |
| 48890 | 6a | -10 to -5°F | 23 km |
| 48845 | 6a | -10 to -5°F | 25 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 USC00204078, at 42.9531, -85.0778, elevation 245 m (805 ft).
- Data quality: Representative (10+ years), 21 years of freeze data.
- Average days per year at or below 32°F: 148.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Greenville 2 NNE (31 km)
- Grand Rapids (39 km)
- Nwsfo Grand Rapids (39 km)
- Hastings (39 km)
- Saint Johns (43 km)
- E Grand Rapids (44 km)
- Lansing Capital City Airport (45 km)
- Charlotte (49 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.