When to plant in Rock Island, IL
USDA Zone 5bRock Island, Illinois frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
In zone 5b, Rock Island gardeners can grow many hardy perennials, while the last and first frost still dictate the annual vegetable calendar.
Frost probability
MOLINE QUAD CITY INTL AP · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Rock Island’s own odds, recorded at MOLINE QUAD CITY INTL AP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 19 | May 4 | Apr 20 | Sep 24 | Oct 7 | Oct 20 |
| 32°F | May 9 | Apr 24 | Apr 9 | Oct 4 | Oct 18 | Oct 28 |
| 28°F | Apr 30 | Apr 12 | Mar 30 | Oct 15 | Oct 27 | Nov 7 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Rock Island, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 16 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Rock Island planting FAQ
When is the last spring frost in Rock Island, IL?
Plan for the last spring frost in Rock Island around April 24 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in Rock Island, IL?
In Rock Island, the first 32°F freeze of fall lands around October 18 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Rock Island in?
Rock Island is in USDA hardiness zone 5b. In zone 5b, winters are cold — pick cold-hardy varieties and protect tender crops.
How long is the growing season in Rock Island?
Rock Island has about 177 frost-free days — a moderate growing season — between the average last spring frost (April 24) and first fall frost (October 18).
When should I plant tomatoes in Rock Island?
For Rock Island, sow tomatoes indoors about February 27–March 13 and move the seedlings out around May 1, after the last spring frost.
Never miss a window in Rock Island
An email when it’s time to start seeds, transplant, and sow — timed to Rock Island’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Moline · 8 km
- Davenport · 10 km
- Bettendorf · 14 km
- East Moline · 17 km
- Muscatine · 41 km
- Clinton · 50 km
- Galesburg · 60 km
- Kewanee · 61 km
Frost dates recorded at MOLINE QUAD CITY INTL AP, 5 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Rock Island, IL — Frost Dates & Zone 5b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00014923. Retrieved from https://blissgarden.com/illinois/rock-island.