When to plant in Blue Island, IL
USDA Zone 6aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Blue Island, Illinois — all computed from Blue Island's nearest NOAA weather station.
Zone 6a means Blue Island sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
Frost probability
CHICAGO MIDWAY AP 3SW · 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 Blue Island’s own odds, recorded at CHICAGO MIDWAY AP 3SW.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 6 | Apr 22 | Apr 9 | Oct 10 | Oct 22 | Nov 3 |
| 32°F | Apr 26 | Apr 10 | Mar 30 | Oct 21 | Nov 1 | Nov 16 |
| 28°F | Apr 14 | Apr 1 | Mar 15 | Oct 30 | Nov 11 | Nov 26 |
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 Blue Island, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 17 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.
Blue Island planting FAQ
When is the last spring frost in Blue Island, IL?
Blue Island's average last spring frost falls near April 10 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Blue Island, IL?
The first fall frost in Blue Island typically arrives around November 1 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Blue Island in?
Blue Island is in USDA hardiness zone 6a. In zone 6a, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Blue Island?
There are roughly 205 frost-free days in Blue Island (a moderate growing season), running from the average last frost around April 10 to the first fall frost near November 1.
When should I plant tomatoes in Blue Island?
In Blue Island, start tomato seeds indoors around February 13–February 27, then transplant seedlings outdoors around April 17 once the danger of frost has passed.
Never miss a window in Blue Island
An email when it’s time to start seeds, transplant, and sow — timed to Blue Island’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Riverdale · 4 km
- Alsip · 5 km
- Midlothian · 5 km
- Crestwood · 5 km
- Harvey · 6 km
- Markham · 6 km
- Evergreen Park · 7 km
- Dolton · 8 km
Frost dates recorded at CHICAGO MIDWAY AP 3SW, 12 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 Blue Island, IL — Frost Dates & Zone 6a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00111577. Retrieved from https://blissgarden.com/illinois/blue-island.