When to plant in North Chicago, IL
USDA Zone 6aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for North Chicago, Illinois — all computed from North Chicago's nearest NOAA weather station.
Zone 6a means North Chicago sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
The average last spring frost in North Chicago is now 7 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
WAUKEGAN · 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 North Chicago’s own odds, recorded at WAUKEGAN.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 27 | May 8 | Apr 25 | Sep 22 | Oct 8 | Oct 24 |
| 32°F | May 14 | Apr 30 | Apr 15 | Sep 30 | Oct 19 | Nov 3 |
| 28°F | May 3 | Apr 20 | Apr 5 | Oct 12 | Oct 30 | Nov 13 |
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 North Chicago, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 19 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.
North Chicago planting FAQ
When is the last spring frost in North Chicago, IL?
North Chicago's average last spring frost falls near April 30 — 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 North Chicago, IL?
Expect North Chicago's first fall frost near October 19 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is North Chicago in?
North Chicago 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 North Chicago?
There are roughly 172 frost-free days in North Chicago (a moderate growing season), running from the average last frost around April 30 to the first fall frost near October 19.
When should I plant tomatoes in North Chicago?
In North Chicago, start tomato seeds indoors around March 5–March 19, then transplant seedlings outdoors around May 7 once the danger of frost has passed.
Never miss a window in North Chicago
An email when it’s time to start seeds, transplant, and sow — timed to North Chicago’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Waukegan · 6 km
- Gurnee · 9 km
- Lake Forest · 9 km
- Libertyville · 10 km
- Gages Lake · 11 km
- Vernon Hills · 12 km
- Mundelein · 14 km
- Beach Park · 14 km
Frost dates recorded at WAUKEGAN, 4 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 North Chicago, IL — Frost Dates & Zone 6a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00119029. Retrieved from https://blissgarden.com/illinois/north-chicago.