Frost dates for Three Rivers, MI
At Three Rivers, the median last spring frost (32°F) is Apr 30 and the median first fall frost is Oct 17, for a typical growing season of 170 days. For a 90% chance that the last frost has passed, wait until May 15. Nearby ZIP codes are in USDA hardiness zone 6a.
- Apr 30Last spring frost (median)50% chance of 32°F after this date
- May 15Safer planting date10% chance of 32°F after this date
- Oct 17First fall frost (median)50% chance of 32°F by this date
- 170 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 25 | May 10 | May 25 |
| 32°F | Apr 16 | Apr 30 | May 15 |
| 28°F | Apr 5 | Apr 19 | May 5 |
| 24°F | Mar 22 | Apr 6 | Apr 22 |
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 23 | Oct 5 | Oct 17 |
| 32°F | Oct 1 | Oct 17 | Nov 1 |
| 28°F | Oct 15 | Oct 31 | Nov 13 |
| 24°F | Oct 28 | Nov 10 | Nov 28 |
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 | 129 days | 148 days | 168 days |
| 32°F | 148 days | 170 days | 189 days |
| 28°F | 172 days | 194 days | 211 days |
| 24°F | 198 days | 217 days | 239 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 |
|---|---|---|---|
| 49093 | 6a | -10 to -5°F | 5 km |
| 49042 | 6a | -10 to -5°F | 8 km |
| 49032 | 6a | -10 to -5°F | 10 km |
| 49099 | 6a | -10 to -5°F | 15 km |
| 49075 | 6a | -10 to -5°F | 16 km |
| 49061 | 6a | -10 to -5°F | 16 km |
| 49067 | 6a | -10 to -5°F | 17 km |
| 49072 | 6a | -10 to -5°F | 18 km |
| 49091 | 6a | -10 to -5°F | 19 km |
| 49095 | 6a | -10 to -5°F | 21 km |
| 49040 | 6a | -10 to -5°F | 26 km |
| 49066 | 6a | -10 to -5°F | 27 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 USC00208184, at 41.9300, -85.6386, elevation 247 m (810 ft).
- Data quality: Standard (24+ years of data), 27 years of freeze data.
- Average days per year at or below 32°F: 145.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Kalamazoo Battle Ck Intl Airport (35 km)
- Dowagiac 1 W (41 km)
- Eau Claire 4 NE (51 km)
- Battle Creek Kellogg Airport (53 km)
- Niles (53 km)
- Coldwater St. School (54 km)
- Gull Lake Biological Station (56 km)
- Bloomingdale (57 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.