Frost dates for Bentley, IL
At Bentley, the median last spring frost (32°F) is Apr 13 and the median first fall frost is Oct 22, for a typical growing season of 191 days. For a 90% chance that the last frost has passed, wait until Apr 30. Nearby ZIP codes are in USDA hardiness zone 6a.
- Apr 13Last spring frost (median)50% chance of 32°F after this date
- Apr 30Safer planting date10% chance of 32°F after this date
- Oct 22First fall frost (median)50% chance of 32°F by this date
- 191 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 11 | Apr 25 | May 10 |
| 32°F | Mar 30 | Apr 13 | Apr 30 |
| 28°F | Mar 18 | Apr 3 | Apr 20 |
| 24°F | Mar 7 | Mar 23 | Apr 8 |
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 25 | Oct 12 | Oct 25 |
| 32°F | Oct 8 | Oct 22 | Nov 4 |
| 28°F | Oct 20 | Nov 1 | Nov 15 |
| 24°F | Oct 28 | Nov 11 | Nov 28 |
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 | 149 days | 170 days | 188 days |
| 32°F | 170 days | 191 days | 210 days |
| 28°F | 191 days | 212 days | 233 days |
| 24°F | 211 days | 232 days | 255 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 |
|---|---|---|---|
| 62321 | 6a | -10 to -5°F | 7 km |
| 62313 | 6a | -10 to -5°F | 10 km |
| 62316 | 6a | -10 to -5°F | 13 km |
| 62380 | 6a | -10 to -5°F | 14 km |
| 62336 | 6a | -10 to -5°F | 15 km |
| 62374 | 6a | -10 to -5°F | 18 km |
| 62367 | 6a | -10 to -5°F | 22 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 USC00110598, at 40.3444, -91.1125, elevation 198 m (650 ft).
- Data quality: Standard (24+ years of data), 26 years of freeze data.
- Average days per year at or below 32°F: 124.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Golden (28 km)
- La Harpe (29 km)
- Quincy Regional Airport (46 km)
- Rushville (53 km)
- Quincy Dam 21 (56 km)
- Gladstone Dam 18 (60 km)
- Prairie City 2s (61 km)
- Perry 6 NW (65 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.