Frost dates for Chicago Midway Airport, IL
At Chicago Midway Airport, the median last spring frost (32°F) is Apr 11 and the median first fall frost is Oct 31, for a typical growing season of 201 days. For a 90% chance that the last frost has passed, wait until Apr 27. Nearby ZIP codes are in USDA hardiness zone 6a.
- Apr 11Last spring frost (median)50% chance of 32°F after this date
- Apr 27Safer planting date10% chance of 32°F after this date
- Oct 31First fall frost (median)50% chance of 32°F by this date
- 201 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 27 |
| 28°F | Mar 15 | Apr 1 | Apr 14 |
| 24°F | Mar 5 | Mar 20 | Apr 3 |
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 8 | Oct 21 | Nov 1 |
| 32°F | Oct 20 | Oct 31 | Nov 14 |
| 28°F | Oct 31 | Nov 11 | Nov 26 |
| 24°F | Nov 7 | Nov 20 | Dec 5 |
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 | 180 days | 198 days |
| 32°F | 181 days | 201 days | 222 days |
| 28°F | 204 days | 225 days | 246 days |
| 24°F | 224 days | 246 days | 268 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 |
|---|---|---|---|
| 60638 | 6a | -10 to -5°F | 2 km |
| 60629 | 6a | -10 to -5°F | 4 km |
| 60632 | 6a | -10 to -5°F | 4 km |
| 60652 | 6a | -10 to -5°F | 5 km |
| 60501 | 6a | -10 to -5°F | 6 km |
| 60804 | 6a | -10 to -5°F | 6 km |
| 60402 | 6a | -10 to -5°F | 6 km |
| 60534 | 6a | -10 to -5°F | 6 km |
| 60636 | 6a | -10 to -5°F | 7 km |
| 60623 | 6a | -10 to -5°F | 7 km |
| 60546 | 6a | -10 to -5°F | 8 km |
| 60513 | 6a | -10 to -5°F | 9 km |
| 60620 | 6a | -10 to -5°F | 10 km |
| 60304 | 6a | -10 to -5°F | 10 km |
| 60644 | 6a | -10 to -5°F | 10 km |
| 60130 | 6a | -10 to -5°F | 11 km |
| 60141 | 6a | -10 to -5°F | 11 km |
| 60155 | 6a | -10 to -5°F | 12 km |
| 60526 | 6a | -10 to -5°F | 12 km |
| 60302 | 6a | -10 to -5°F | 12 km |
| 60153 | 6a | -10 to -5°F | 13 km |
| 60305 | 6a | -10 to -5°F | 13 km |
| 60154 | 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 USW00014819, at 41.7861, -87.7522, elevation 186 m (612 ft).
- Data quality: Representative (10+ years), 23 years of freeze data.
- Average days per year at or below 32°F: 106.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Chicago Midway Airport 3sw (6 km)
- Little Red School Hse (13 km)
- Chicago Northerly Island (14 km)
- Lisle-Morton Arboretum (27 km)
- Wheaton 3 SE (27 km)
- Chicago Ohare Intl Airport (28 km)
- Park Forest (33 km)
- Romeoville WFO (34 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.