Frost dates for Kaskaskia River Navigation Lock, IL
At Kaskaskia River Navigation Lock, the median last spring frost (32°F) is Apr 8 and the median first fall frost is Oct 30, for a typical growing season of 202 days. For a 90% chance that the last frost has passed, wait until Apr 25. Nearby ZIP codes are in USDA hardiness zones 6b to 7a.
- Apr 8Last spring frost (median)50% chance of 32°F after this date
- Apr 25Safer planting date10% chance of 32°F after this date
- Oct 30First fall frost (median)50% chance of 32°F by this date
- 202 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 5 | Apr 20 | May 5 |
| 32°F | Mar 22 | Apr 8 | Apr 25 |
| 28°F | Mar 9 | Mar 28 | Apr 13 |
| 24°F | Feb 26 | Mar 14 | Apr 2 |
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 | Oct 4 | Oct 18 | Oct 31 |
| 32°F | Oct 15 | Oct 30 | Nov 13 |
| 28°F | Oct 27 | Nov 10 | Nov 30 |
| 24°F | Nov 5 | Nov 24 | Dec 12 |
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 | 159 days | 179 days | 200 days |
| 32°F | 180 days | 202 days | 226 days |
| 28°F | 204 days | 228 days | 256 days |
| 24°F | 228 days | 254 days | 280 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 |
|---|---|---|---|
| 62261 | 7a | 0 to 5°F | 5 km |
| 62241 | 7a | 0 to 5°F | 6 km |
| 62242 | 7a | 0 to 5°F | 13 km |
| 62233 | 7a | 0 to 5°F | 15 km |
| 62277 | 7a | 0 to 5°F | 19 km |
| 63670 | 6b | -5 to 0°F | 21 km |
| 62279 | 7a | 0 to 5°F | 24 km |
| 62278 | 7a | 0 to 5°F | 25 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 USC00114629, at 37.9833, -89.9469, elevation 116 m (380 ft).
- Data quality: Representative (10+ years), 25 years of freeze data.
- Average days per year at or below 32°F: 99.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Sparta 1 W (25 km)
- Belleville Siu Rsch (60 km)
- Nashville 1 E (65 km)
- Carbondale Southern Il Airport (65 km)
- Du Quoin 4 SE (66 km)
- Cahokia St. Louis Airport (68 km)
- Cahokia (68 km)
- Carbondale Sewage Plant (74 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.