Frost dates for Mount Vernon 3 NE, IL
At Mount Vernon 3 NE, the median last spring frost (32°F) is Apr 11 and the median first fall frost is Oct 22, for a typical growing season of 193 days. For a 90% chance that the last frost has passed, wait until Apr 26. Nearby ZIP codes are in USDA hardiness zone 6b.
- Apr 11Last spring frost (median)50% chance of 32°F after this date
- Apr 26Safer planting date10% chance of 32°F after this date
- Oct 22First fall frost (median)50% chance of 32°F by this date
- 193 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 9 | Apr 23 | May 8 |
| 32°F | Mar 30 | Apr 11 | Apr 26 |
| 28°F | Mar 16 | Apr 1 | Apr 17 |
| 24°F | Mar 4 | Mar 22 | 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 | Sep 30 | Oct 12 | Oct 25 |
| 32°F | Oct 9 | Oct 22 | Nov 1 |
| 28°F | Oct 20 | Nov 1 | Nov 16 |
| 24°F | Oct 31 | Nov 13 | 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 | 153 days | 172 days | 191 days |
| 32°F | 175 days | 193 days | 211 days |
| 28°F | 194 days | 214 days | 235 days |
| 24°F | 215 days | 237 days | 259 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 |
|---|---|---|---|
| 62864 | 6b | -5 to 0°F | 5 km |
| 62872 | 6b | -5 to 0°F | 10 km |
| 62814 | 6b | -5 to 0°F | 11 km |
| 62889 | 6b | -5 to 0°F | 12 km |
| 62810 | 6b | -5 to 0°F | 19 km |
| 62851 | 6b | -5 to 0°F | 19 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 USC00115943, at 38.3483, -88.8533, elevation 149 m (490 ft).
- Data quality: Standard (24+ years of data), 28 years of freeze data.
- Average days per year at or below 32°F: 108.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Iuka 12 SW (19 km)
- Salem (33 km)
- Benton 2 N (35 km)
- Rend Lake Dam (36 km)
- McLeansboro (40 km)
- Nashville 1 E (44 km)
- Fairfield Radio Wfiw (46 km)
- Flora 5 NW (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.