Frost dates for Port Hope, MI
At Port Hope, the median last spring frost (32°F) is Apr 28 and the median first fall frost is Nov 3, for a typical growing season of 187 days. For a 90% chance that the last frost has passed, wait until May 14. Nearby ZIP codes are in USDA hardiness zone 6a.
- Apr 28Last spring frost (median)50% chance of 32°F after this date
- May 14Safer planting date10% chance of 32°F after this date
- Nov 3First fall frost (median)50% chance of 32°F by this date
- 187 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 26 | May 10 | May 22 |
| 32°F | Apr 13 | Apr 28 | May 14 |
| 28°F | Apr 1 | Apr 15 | Apr 30 |
| 24°F | Mar 17 | Apr 2 | Apr 17 |
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 | Oct 5 | Oct 22 | Nov 3 |
| 32°F | Oct 21 | Nov 3 | Nov 15 |
| 28°F | Nov 2 | Nov 14 | Nov 28 |
| 24°F | Nov 9 | Nov 25 | Dec 10 |
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 | 143 days | 162 days | 183 days |
| 32°F | 166 days | 187 days | 207 days |
| 28°F | 192 days | 213 days | 234 days |
| 24°F | 215 days | 237 days | 260 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 |
|---|---|---|---|
| 48468 | 6a | -10 to -5°F | 9 km |
| 48467 | 6a | -10 to -5°F | 15 km |
| 48445 | 6a | -10 to -5°F | 18 km |
| 48432 | 6a | -10 to -5°F | 20 km |
| 48441 | 6a | -10 to -5°F | 26 km |
| 48413 | 6a | -10 to -5°F | 29 km |
| 48470 | 6a | -10 to -5°F | 32 km |
| 48725 | 6a | -10 to -5°F | 34 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 USW00094898, at 44.0219, -82.7931, elevation 180 m (590 ft).
- Data quality: Representative (10+ years), 20 years of freeze data.
- Average days per year at or below 32°F: 126.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Port Hope (10 km)
- Port Austin Wastewater Plant (14 km)
- Harbor Beach 1 SSE (24 km)
- Filion 5nnw (26 km)
- Bad Axe (29 km)
- Cass City 1 SSW (58 km)
- E Tawas (64 km)
- Sandusky (67 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.