Frost dates for Hancock Houghton Co Airport, MI
At Hancock Houghton Co Airport, the median last spring frost (32°F) is May 17 and the median first fall frost is Oct 1, for a typical growing season of 138 days. For a 90% chance that the last frost has passed, wait until Jun 3. Nearby ZIP codes are in USDA hardiness zone 5b.
- May 17Last spring frost (median)50% chance of 32°F after this date
- Jun 3Safer planting date10% chance of 32°F after this date
- Oct 1First fall frost (median)50% chance of 32°F by this date
- 138 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 16 | Jun 1 | Jun 13 |
| 32°F | May 1 | May 17 | Jun 3 |
| 28°F | Apr 19 | May 2 | May 20 |
| 24°F | Apr 8 | Apr 22 | May 6 |
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 3 | Sep 21 | Oct 5 |
| 32°F | Sep 16 | Oct 1 | Oct 18 |
| 28°F | Sep 28 | Oct 14 | Nov 1 |
| 24°F | Oct 13 | Oct 30 | Nov 14 |
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 | 90 days | 113 days | 133 days |
| 32°F | 116 days | 138 days | 159 days |
| 28°F | 141 days | 164 days | 185 days |
| 24°F | 166 days | 190 days | 211 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 |
|---|---|---|---|
| 49934 | 5b | -15 to -10°F | 3 km |
| 49922 | 5b | -15 to -10°F | 5 km |
| 49930 | 5b | -15 to -10°F | 8 km |
| 49913 | 5b | -15 to -10°F | 8 km |
| 49945 | 5b | -15 to -10°F | 11 km |
| 49921 | 5b | -15 to -10°F | 11 km |
| 49942 | 5b | -15 to -10°F | 12 km |
| 49931 | 5b | -15 to -10°F | 12 km |
| 49901 | 5b | -15 to -10°F | 16 km |
| 49917 | 5b | -15 to -10°F | 16 km |
| 49905 | 5b | -15 to -10°F | 18 km |
| 49805 | 5b | -15 to -10°F | 22 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 USW00014858, at 47.1658, -88.4808, elevation 324 m (1,063 ft).
- Data quality: Standard (24+ years of data), 30 years of freeze data.
- Average days per year at or below 32°F: 175.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Jacobsville (18 km)
- Baraga 7nw (40 km)
- Copper Harbor (56 km)
- Herman (56 km)
- Greenland 6n (57 km)
- Copper Harbor Fort Wilkins (57 km)
- Alberta Ford For Center (58 km)
- Ontonagon 6 SE (66 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.