Frost dates for Sidell 4n, IL
At Sidell 4n, 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 3. Nearby ZIP codes are in USDA hardiness zone 6a.
- Apr 19Last 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
- 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 29 | May 13 |
| 32°F | Apr 4 | Apr 19 | May 3 |
| 28°F | Mar 24 | Apr 6 | Apr 21 |
| 24°F | Mar 11 | Mar 28 | Apr 11 |
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 21 |
| 32°F | Oct 5 | Oct 19 | Nov 1 |
| 28°F | Oct 15 | Oct 30 | Nov 14 |
| 24°F | Oct 28 | Nov 9 | Nov 27 |
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 | 143 days | 162 days | 178 days |
| 32°F | 162 days | 181 days | 200 days |
| 28°F | 183 days | 203 days | 222 days |
| 24°F | 205 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 |
|---|---|---|---|
| 61841 | 6a | -10 to -5°F | 7 km |
| 61876 | 6a | -10 to -5°F | 7 km |
| 61850 | 6a | -10 to -5°F | 8 km |
| 61810 | 6a | -10 to -5°F | 10 km |
| 61817 | 6a | -10 to -5°F | 12 km |
| 61816 | 6a | -10 to -5°F | 16 km |
| 61940 | 6a | -10 to -5°F | 18 km |
| 61870 | 6a | -10 to -5°F | 19 km |
| 61932 | 6a | -10 to -5°F | 19 km |
| 61942 | 6a | -10 to -5°F | 23 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 USC00117952, at 39.9678, -87.8228, elevation 205 m (672 ft).
- Data quality: Representative (10+ years), 17 years of freeze data.
- Average days per year at or below 32°F: 126.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Ogden (19 km)
- Danville (24 km)
- Champaign 3s (38 km)
- Champaign Willard Airport (40 km)
- Paris Stp (41 km)
- Tuscola (44 km)
- Champaign 9 SW (48 km)
- Rantoul (48 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.