Frost dates for Bloomington Monroe Co Airport, IN
At Bloomington Monroe Co Airport, the median last spring frost (32°F) is Apr 17 and the median first fall frost is Oct 22, for a typical growing season of 185 days. For a 90% chance that the last frost has passed, wait until May 5. Nearby ZIP codes are in USDA hardiness zone 6b.
- Apr 17Last spring frost (median)50% chance of 32°F after this date
- May 5Safer planting date10% chance of 32°F after this date
- Oct 22First fall frost (median)50% chance of 32°F by this date
- 185 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 13 | Apr 30 | May 16 |
| 32°F | Apr 3 | Apr 17 | May 5 |
| 28°F | Mar 21 | Apr 4 | Apr 21 |
| 24°F | Mar 8 | Mar 26 | Apr 8 |
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 28 | Oct 11 | Oct 25 |
| 32°F | Oct 8 | Oct 22 | Nov 2 |
| 28°F | Oct 19 | Nov 1 | Nov 16 |
| 24°F | Oct 31 | Nov 13 | Dec 1 |
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 | 141 days | 163 days | 185 days |
| 32°F | 163 days | 185 days | 205 days |
| 28°F | 187 days | 208 days | 228 days |
| 24°F | 211 days | 234 days | 258 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 |
|---|---|---|---|
| 47403 | 6b | -5 to 0°F | 5 km |
| 47459 | 6b | -5 to 0°F | 12 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 USW00003893, at 39.1333, -86.6167, elevation 257 m (844 ft).
- Data quality: Representative (10+ years), 22 years of freeze data.
- Average days per year at or below 32°F: 108.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Bloomington Indiana Univ (9 km)
- Spencer (21 km)
- Bedford 5 WNW (28 km)
- Oolitic Purdue Ex Fm (28 km)
- Martinsville 2 SW (33 km)
- Crane Nsa (35 km)
- Elnora (50 km)
- Shakamak State Park (54 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.