When to plant in Westchester, IL
USDA Zone 6aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Westchester, Illinois — all computed from Westchester's nearest NOAA weather station.
Zone 6a means Westchester 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 · 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 Westchester’s own odds, recorded at CHICAGO MIDWAY AP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 8 | Apr 23 | Apr 9 | Oct 8 | Oct 21 | Nov 1 |
| 32°F | Apr 27 | Apr 11 | Mar 30 | Oct 20 | Oct 31 | Nov 14 |
| 28°F | Apr 14 | Apr 1 | Mar 15 | Oct 31 | 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 Westchester, 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.
Westchester planting FAQ
When is the last spring frost in Westchester, IL?
Plan for the last spring frost in Westchester around April 11 (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 Westchester, IL?
In Westchester, the first 32°F freeze of fall lands around October 31 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Westchester in?
Westchester 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 Westchester?
There are roughly 203 frost-free days in Westchester (a moderate growing season), running from the average last frost around April 11 to the first fall frost near October 31.
When should I plant tomatoes in Westchester?
In Westchester, start tomato seeds indoors around February 14–February 28, then transplant seedlings outdoors around April 18 once the danger of frost has passed.
Never miss a window in Westchester
An email when it’s time to start seeds, transplant, and sow — timed to Westchester’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- La Grange Park · 3 km
- Bellwood · 4 km
- Brookfield · 4 km
- La Grange · 5 km
- Maywood · 5 km
- Western Springs · 5 km
- Hinsdale · 6 km
- Melrose Park · 6 km
Frost dates recorded at CHICAGO MIDWAY AP, 13 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 Westchester, IL — Frost Dates & Zone 6a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00014819. Retrieved from https://blissgarden.com/illinois/westchester.