USDA hardiness zones — 2023 map
Illinois hardiness zones — USDA planting zone map + what to grow
Zones 5a-7a · most of Illinois is zone 6a · Midwest region
IllinoisUSDA zone range & map
On the 2023 USDA Plant Hardiness Zone Map, Illinois spans zones 5a-7a. The map shades the state from the northern counties near the Wisconsin line (zone 5a) through to the far south near Cairo and Carbondale (zone 7a). The single most common half-zone across the populated state is zone 6a — that is the figure to use if you only remember one number for Illinois. Illinois has a productive continental Midwest climate. The south of the state runs nearly two half-zones warmer than the Chicago area.
| USDA zone range | Zones 5a-7a |
|---|---|
| Most common zone | Zone 6a |
| Coldest area | the northern counties near the Wisconsin line (zone 5a) |
| Warmest area | the far south near Cairo and Carbondale (zone 7a) |
| Average last spring frost | late April |
| Average first fall frost | mid-October |
Source: USDA 2023 Plant Hardiness Zone Map (1991-2020 normals). Frost averages: NOAA/NCEI 1991-2020 climate normals. Local ZIP-level zones and frost dates can differ from these statewide figures.
Illinois hardiness zones by major city
Zones shift across Illinois with elevation and distance from the coast. Here is the 2023 USDA half-zone for the largest cities:
| City | USDA zone |
|---|---|
| Chicago | Zone 6a |
| Springfield | Zone 6a |
| Peoria | Zone 5b |
| Rockford | Zone 5b |
| Carbondale | Zone 7a |
Need your exact zone? Run the ZIP-code zone finder for a precise half-zone and frost dates for your address.
ZIP-code zones in Illinois
Statewide ranges hide a lot. Tap your area for its exact USDA half-zone, last and first frost dates, and what to plant now:
- McHenry 60050 — Zone 5b
- Addison 60101 — Zone 6a
- Elgin 60123 — Zone 5b
- Villa Park 60181 — Zone 6a
- Wheaton 60187 — Zone 6a
- Oak Park 60302 — Zone 6a
- Oak Lawn 60453 — Zone 6a
- Aurora 60506 — Zone 6a
- Naperville 60565 — Zone 6a
- Chicago 60601 — Zone 6a
- Chicago (Near North) 60611 — Zone 6a
- Chicago (Lincoln Park) 60614 — Zone 6a
- Chicago (Avondale) 60618 — Zone 6a
- Chicago (Albany Park) 60625 — Zone 6a
- Chicago (Chicago Lawn) 60629 — Zone 6a
- Chicago (Brighton Park) 60632 — Zone 6a
- Chicago (Dunning) 60634 — Zone 6a
- Chicago (Belmont Cragin) 60639 — Zone 6a
- Chicago (Logan Square) 60647 — Zone 6a
- Chicago (Humboldt Park) 60651 — Zone 6a
- Rockford 61101 — Zone 5b
- Peoria 61602 — Zone 5b
- Urbana 61801 — Zone 6a
- Champaign 61820 — Zone 6a
- O'Fallon 62269 — Zone 6b
- Springfield 62701 — Zone 6a
- Carbondale 62901 — Zone 7a
What Illinois's zone range means for planting
Your hardiness zone tells you which perennials, shrubs, and trees will survive a typical Illinois winter, and it anchors when tender crops can go outside. Because Illinois spans 5a-7a, two gardeners in the same state can have very different planting calendars.
- Pick perennials hardy to your local zone. Across most of Illinois that means at least zone 6a; gardeners in the northern counties near the Wisconsin line (zone 5a) should choose hardier plants.
- Anchor tender crops to your frost dates. With a last spring frost around late April and first fall frost around mid-October, set out tomatoes, peppers, and basil after the last frost and protect them before the first.
- Adjust for your microclimate. Urban heat, a south-facing slope, or a cold valley pocket can shift your effective zone and frost dates by a half-zone or more from the statewide figure.
Find your exact zone in Illinois
The 5a-7a range is statewide. Growli pins your hardiness zone and frost dates to your exact ZIP code and sends a push notification before any forecast frost night for your saved location.
Frequently asked questions
What hardiness zone is Illinois?
Illinois spans USDA hardiness zones 5a-7a on the 2023 USDA Plant Hardiness Zone Map. The most common zone — covering the largest share of the populated state — is zone 6a. The coldest areas are the northern counties near the Wisconsin line (zone 5a) and the warmest are the far south near Cairo and Carbondale (zone 7a).
When is the last frost in Illinois?
Across most of Illinois the average last spring frost falls around late April and the first fall frost around mid-October. These are statewide averages — colder, higher areas run later in spring and earlier in fall, so check a ZIP-level estimate for your exact spot.
What grows well in Illinois?
Illinois has a productive continental Midwest climate. The south of the state runs nearly two half-zones warmer than the Chicago area. Match plants to your local half-zone within the 5a-7a range: choose varieties hardy to at least zone 6a for reliable overwintering, and time tender crops around your local frost dates. The zone 6 planting guide lists vegetables, fruit, and ornamentals suited to most of the state.
Why does Illinois have more than one hardiness zone?
Hardiness zones track the average annual coldest temperature, which changes with latitude, elevation, distance from water, and urban heat. That is why Illinois ranges from the northern counties near the Wisconsin line (zone 5a) to the far south near Cairo and Carbondale (zone 7a) — a span of 5a-7a — even though it is a single state.
Did Illinois's hardiness zone change in 2023?
The USDA updated the Plant Hardiness Zone Map in November 2023 using 1991-2020 climate data. About half the country, including parts of Illinois, shifted to the next warmer half-zone versus the 2012 map. The 5a-7a range here reflects the current 2023 map. Always confirm your address against the official USDA map for plant-survival decisions.