Frost dates for Jacksonville 2, IL
At Jacksonville 2, the median last spring frost (32°F) is Apr 17 and the median first fall frost is Oct 21, for a typical growing season of 186 days. For a 90% chance that the last frost has passed, wait until May 1. Nearby ZIP codes are in USDA hardiness zone 6a.
- Apr 17Last spring frost (median)50% chance of 32°F after this date
- May 1Safer planting date10% chance of 32°F after this date
- Oct 21First fall frost (median)50% chance of 32°F by this date
- 186 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 14 | Apr 27 | May 11 |
| 32°F | Apr 3 | Apr 17 | May 1 |
| 28°F | Mar 22 | Apr 6 | Apr 21 |
| 24°F | Mar 10 | 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 27 | Oct 12 | Oct 23 |
| 32°F | Oct 9 | Oct 21 | Nov 1 |
| 28°F | Oct 18 | Oct 31 | Nov 14 |
| 24°F | Oct 29 | Nov 8 | Nov 26 |
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 | 147 days | 167 days | 183 days |
| 32°F | 167 days | 186 days | 204 days |
| 28°F | 188 days | 208 days | 229 days |
| 24°F | 208 days | 228 days | 252 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 |
|---|---|---|---|
| 62695 | 6a | -10 to -5°F | 10 km |
| 62668 | 6a | -10 to -5°F | 16 km |
| 62628 | 6a | -10 to -5°F | 17 km |
| 62631 | 6a | -10 to -5°F | 17 km |
| 62638 | 6a | -10 to -5°F | 17 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 USC00114447, at 39.7133, -90.2286, elevation 191 m (626 ft).
- Data quality: Representative (10+ years), 15 years of freeze data.
- Average days per year at or below 32°F: 122.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Jacksonville 2e (4 km)
- Winchester (21 km)
- White Hall 1 E (33 km)
- Athens 4sw (44 km)
- Virden (46 km)
- Petersburg 1e (48 km)
- Springfield #2 (48 km)
- Springfield Capital Airport (49 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.