Frost dates for Brookport Dam 52, IL
At Brookport Dam 52, the median last spring frost (32°F) is Apr 6 and the median first fall frost is Oct 27, for a typical growing season of 203 days. For a 90% chance that the last frost has passed, wait until Apr 23. Nearby ZIP codes are in USDA hardiness zone 7a.
- Apr 6Last spring frost (median)50% chance of 32°F after this date
- Apr 23Safer planting date10% chance of 32°F after this date
- Oct 27First fall frost (median)50% chance of 32°F by this date
- 203 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 3 | Apr 19 | May 4 |
| 32°F | Mar 21 | Apr 6 | Apr 23 |
| 28°F | Mar 8 | Mar 27 | Apr 11 |
| 24°F | Feb 25 | Mar 16 | 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 6 | Oct 18 | Oct 30 |
| 32°F | Oct 15 | Oct 27 | Nov 9 |
| 28°F | Oct 24 | Nov 5 | Nov 21 |
| 24°F | Nov 1 | Nov 16 | Dec 4 |
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 | 161 days | 182 days | 203 days |
| 32°F | 182 days | 203 days | 224 days |
| 28°F | 204 days | 223 days | 247 days |
| 24°F | 220 days | 246 days | 271 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 |
|---|---|---|---|
| 62960 | 7a | 0 to 5°F | 13 km |
| 42003 | 7a | 0 to 5°F | 15 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 USC00110993, at 37.1275, -88.6531, elevation 101 m (330 ft).
- Data quality: Standard (24+ years of data), 26 years of freeze data.
- Average days per year at or below 32°F: 83.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Smithland L&d (20 km)
- Dixon Springs Agric Center (35 km)
- Grand Chain Dam 53 (36 km)
- Rosiclare 5nw (44 km)
- Cairo 3n (48 km)
- Anna 2 NNE (65 km)
- Harrisburg (69 km)
- Carbondale Sewage Plant (81 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.