Frost dates for Benton Harbor Airport, MI
At Benton Harbor Airport, the median last spring frost (32°F) is May 4 and the median first fall frost is Oct 17, for a typical growing season of 164 days. For a 90% chance that the last frost has passed, wait until May 22. Nearby ZIP codes are in USDA hardiness zones 6a to 6b.
- May 4Last spring frost (median)50% chance of 32°F after this date
- May 22Safer planting date10% chance of 32°F after this date
- Oct 17First fall frost (median)50% chance of 32°F by this date
- 164 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 17 | Jun 2 |
| 32°F | Apr 19 | May 4 | May 22 |
| 28°F | Apr 7 | Apr 22 | May 10 |
| 24°F | Mar 25 | Apr 9 | Apr 23 |
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 19 | Oct 3 | Oct 18 |
| 32°F | Sep 30 | Oct 17 | Nov 1 |
| 28°F | Oct 17 | Nov 1 | Nov 16 |
| 24°F | Oct 31 | Nov 13 | Dec 3 |
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 | 116 days | 139 days | 161 days |
| 32°F | 141 days | 164 days | 187 days |
| 28°F | 168 days | 192 days | 212 days |
| 24°F | 196 days | 218 days | 242 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 |
|---|---|---|---|
| 49022 | 6b | -5 to 0°F | 5 km |
| 49084 | 6b | -5 to 0°F | 7 km |
| 49085 | 6b | -5 to 0°F | 8 km |
| 49126 | 6a | -10 to -5°F | 11 km |
| 49038 | 6b | -5 to 0°F | 12 km |
| 49127 | 6b | -5 to 0°F | 16 km |
| 49111 | 6a | -10 to -5°F | 16 km |
| 49098 | 6a | -10 to -5°F | 16 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 USW00094871, at 42.1244, -86.4267, elevation 196 m (643 ft).
- Data quality: Standard (24+ years of data), 24 years of freeze data.
- Average days per year at or below 32°F: 127.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Benton Harbor Airport (0 km)
- Eau Claire 4 NE (19 km)
- Dowagiac 1 W (29 km)
- S Haven (33 km)
- Niles (34 km)
- Bloomingdale (48 km)
- Three Rivers (69 km)
- Allegan 5ne (73 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.