Frost dates for Salem, IL
At Salem, the median last spring frost (32°F) is Apr 9 and the median first fall frost is Oct 26, for a typical growing season of 197 days. For a 90% chance that the last frost has passed, wait until Apr 23. Nearby ZIP codes are in USDA hardiness zone 6b.
- Apr 9Last spring frost (median)50% chance of 32°F after this date
- Apr 23Safer planting date10% chance of 32°F after this date
- Oct 26First fall frost (median)50% chance of 32°F by this date
- 197 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 7 | Apr 21 | May 6 |
| 32°F | Mar 25 | Apr 9 | Apr 23 |
| 28°F | Mar 14 | Mar 30 | Apr 14 |
| 24°F | Mar 4 | Mar 19 | Apr 4 |
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 3 | Oct 17 | Oct 28 |
| 32°F | Oct 13 | Oct 26 | Nov 6 |
| 28°F | Oct 23 | Nov 3 | Nov 20 |
| 24°F | Nov 1 | Nov 15 | Dec 3 |
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 | 157 days | 176 days | 196 days |
| 32°F | 179 days | 197 days | 217 days |
| 28°F | 198 days | 219 days | 241 days |
| 24°F | 218 days | 240 days | 264 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 |
|---|---|---|---|
| 62881 | 6b | -5 to 0°F | 2 km |
| 62870 | 6b | -5 to 0°F | 9 km |
| 62807 | 6b | -5 to 0°F | 12 km |
| 62882 | 6b | -5 to 0°F | 15 km |
| 62849 | 6b | -5 to 0°F | 16 km |
| 62854 | 6b | -5 to 0°F | 17 km |
| 62875 | 6b | -5 to 0°F | 20 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 USC00117636, at 38.6403, -88.9458, elevation 168 m (550 ft).
- Data quality: Standard (24+ years of data), 28 years of freeze data.
- Average days per year at or below 32°F: 102.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Iuka 12 SW (16 km)
- Flora 5 NW (33 km)
- Mount Vernon 3 NE (33 km)
- Brownstown 4 SW (35 km)
- Carlyle Rsvr (36 km)
- Vandalia (38 km)
- Flora (41 km)
- Nashville 1 E (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.