Frost dates for Athens 4sw, IL
At Athens 4sw, the median last spring frost (32°F) is Apr 19 and the median first fall frost is Oct 19, for a typical growing season of 181 days. For a 90% chance that the last frost has passed, wait until May 4. Nearby ZIP codes are in USDA hardiness zone 6a.
- Apr 19Last spring frost (median)50% chance of 32°F after this date
- May 4Safer planting date10% chance of 32°F after this date
- Oct 19First fall frost (median)50% chance of 32°F by this date
- 181 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 17 | Apr 30 | May 14 |
| 32°F | Apr 6 | Apr 19 | May 4 |
| 28°F | Mar 24 | Apr 8 | Apr 23 |
| 24°F | Mar 11 | Mar 30 | Apr 12 |
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 25 | Oct 9 | Oct 22 |
| 32°F | Oct 5 | Oct 19 | Oct 31 |
| 28°F | Oct 14 | Oct 30 | Nov 17 |
| 24°F | Oct 28 | Nov 11 | Nov 30 |
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 | 161 days | 180 days |
| 32°F | 159 days | 181 days | 201 days |
| 28°F | 181 days | 204 days | 225 days |
| 24°F | 206 days | 228 days | 251 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 |
|---|---|---|---|
| 62677 | 6a | -10 to -5°F | 11 km |
| 62613 | 6a | -10 to -5°F | 13 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 USC00110306, at 39.9275, -89.7964, elevation 181 m (594 ft).
- Data quality: Representative (10+ years), 11 years of freeze data.
- Average days per year at or below 32°F: 121.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Petersburg 1e (10 km)
- Springfield Capital Airport (13 km)
- Springfield #2 (18 km)
- Mason City 4se (29 km)
- Jacksonville 2e (40 km)
- Jacksonville 2 (44 km)
- Lincoln (46 km)
- Virden (47 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.