Frost dates for Aurora, IL
At Aurora, the median last spring frost (32°F) is Apr 19 and the median first fall frost is Oct 23, for a typical growing season of 185 days. For a 90% chance that the last frost has passed, wait until May 4. Nearby ZIP codes are in USDA hardiness zone 5b.
- Apr 19Last spring frost (median)50% chance of 32°F after this date
- May 4Safer planting date10% chance of 32°F after this date
- Oct 23First fall frost (median)50% chance of 32°F by this date
- 185 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 | May 1 | May 19 |
| 32°F | Apr 5 | Apr 19 | May 4 |
| 28°F | Mar 25 | Apr 8 | Apr 23 |
| 24°F | Mar 11 | Mar 30 | Apr 13 |
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 29 | Oct 13 | Oct 25 |
| 32°F | Oct 9 | Oct 23 | Nov 3 |
| 28°F | Oct 21 | Nov 2 | Nov 16 |
| 24°F | Nov 1 | Nov 12 | Nov 26 |
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 | 164 days | 183 days |
| 32°F | 164 days | 185 days | 205 days |
| 28°F | 186 days | 207 days | 228 days |
| 24°F | 209 days | 229 days | 250 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 |
|---|---|---|---|
| 60505 | 5b | -15 to -10°F | 2 km |
| 60502 | 5b | -15 to -10°F | 4 km |
| 60542 | 5b | -15 to -10°F | 5 km |
| 60539 | 5b | -15 to -10°F | 5 km |
| 60519 | 5b | -15 to -10°F | 6 km |
| 60506 | 5b | -15 to -10°F | 6 km |
| 60538 | 5b | -15 to -10°F | 6 km |
| 60504 | 5b | -15 to -10°F | 7 km |
| 60510 | 5b | -15 to -10°F | 7 km |
| 60563 | 5b | -15 to -10°F | 9 km |
| 60503 | 5b | -15 to -10°F | 9 km |
| 60543 | 5b | -15 to -10°F | 13 km |
| 60564 | 5b | -15 to -10°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 USC00110338, at 41.7803, -88.3092, elevation 201 m (660 ft).
- Data quality: Standard (24+ years of data), 28 years of freeze data.
- Average days per year at or below 32°F: 134.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Chicago Aurora Muni Airport (14 km)
- West Chicago Dupage Airport (16 km)
- Lisle-Morton Arboretum (20 km)
- Wheaton 3 SE (20 km)
- Romeoville WFO (27 km)
- Streamwood (29 km)
- Elgin (31 km)
- Joliet Brandon Rd Dam (35 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.