When to plant in Brookfield, IL
USDA Zone 6aEverything below — frost dates, hardiness zone, and what to plant when in Brookfield, Illinois — is derived from the closest NOAA station with complete climate normals.
In zone 6a, Brookfield gardeners can grow many hardy perennials, while the last and first frost still dictate the annual vegetable calendar.
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 Brookfield’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 Brookfield, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 13 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.
Brookfield planting FAQ
When is the last spring frost in Brookfield, IL?
Brookfield's average last spring frost falls near April 11 — 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 Brookfield, IL?
Expect Brookfield's first fall frost near October 31 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Brookfield in?
Brookfield 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 Brookfield?
Brookfield has about 203 frost-free days — a moderate growing season — between the average last spring frost (April 11) and first fall frost (October 31).
When should I plant tomatoes in Brookfield?
For Brookfield, sow tomatoes indoors about February 14–February 28 and move the seedlings out around April 18, after the last spring frost.
Never miss a window in Brookfield
An email when it’s time to start seeds, transplant, and sow — timed to Brookfield’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- La Grange Park · 2 km
- Lyons · 3 km
- La Grange · 3 km
- Westchester · 4 km
- Summit · 5 km
- Western Springs · 5 km
- Berwyn · 5 km
- Forest Park · 5 km
Frost dates recorded at CHICAGO MIDWAY AP, 9 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 Brookfield, IL — Frost Dates & Zone 6a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00014819. Retrieved from https://blissgarden.com/illinois/brookfield.