Frost dates for Havana, IL
At Havana, the median last spring frost (32°F) is Apr 17 and the median first fall frost is Oct 19, for a typical growing season of 185 days. For a 90% chance that the last frost has passed, wait until May 3. Nearby ZIP codes are in USDA hardiness zone 6a.
- Apr 17Last spring frost (median)50% chance of 32°F after this date
- May 3Safer planting date10% chance of 32°F after this date
- Oct 19First fall frost (median)50% chance of 32°F by this date
- 185 daysGrowing season (median)between 32°F freezes
USDA hardiness zone 6a (-10 to -5°F) · see all zone 6a frost dates
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 26 | May 11 |
| 32°F | Apr 2 | Apr 17 | May 3 |
| 28°F | Mar 22 | Apr 5 | Apr 21 |
| 24°F | Mar 11 | Mar 28 | Apr 10 |
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 24 | Oct 8 | Oct 21 |
| 32°F | Oct 1 | Oct 19 | Oct 31 |
| 28°F | Oct 15 | Oct 29 | Nov 13 |
| 24°F | Oct 26 | Nov 9 | Nov 25 |
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 | 142 days | 163 days | 182 days |
| 32°F | 162 days | 185 days | 202 days |
| 28°F | 185 days | 204 days | 226 days |
| 24°F | 206 days | 226 days | 249 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 |
|---|---|---|---|
| 62644 | 6a | -10 to -5°F | 2 km |
| 61542 | 6a | -10 to -5°F | 10 km |
| 61543 | 6a | -10 to -5°F | 15 km |
| 61567 | 6a | -10 to -5°F | 16 km |
| 62655 | 6a | -10 to -5°F | 16 km |
| 61519 | 6a | -10 to -5°F | 18 km |
| 62617 | 6a | -10 to -5°F | 19 km |
| 61441 | 6a | -10 to -5°F | 19 km |
| 62633 | 6a | -10 to -5°F | 19 km |
| 61524 | 6a | -10 to -5°F | 21 km |
| 61563 | 6a | -10 to -5°F | 21 km |
| 61532 | 6a | -10 to -5°F | 22 km |
| 61501 | 6a | -10 to -5°F | 23 km |
| 61427 | 6a | -10 to -5°F | 24 km |
| 61520 | 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 USC00113940, at 40.3031, -90.0647, elevation 141 m (463 ft).
- Data quality: Representative (10+ years), 14 years of freeze data.
- Average days per year at or below 32°F: 132.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Petersburg 1E (37 km)
- Mason City 4SE (38 km)
- Rushville (46 km)
- Prairie City 2S (47 km)
- Athens 4SW (48 km)
- Avon (51 km)
- Peoria Gtr Peoria Airport (52 km)
- Springfield Capital Airport (60 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.