When to plant in Macomb, IL
USDA Zone 6aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Macomb, Illinois — all computed from Macomb's nearest NOAA weather station.
These dates come from a station roughly 23 km away, the closest with full normals; terrain around Macomb (elevation, water, pavement) can move your real frost dates a few days either way. In zone 6a, Macomb gardeners can grow many hardy perennials, while the last and first frost still dictate the annual vegetable calendar.
Frost probability
PRAIRIE CITY 2S · 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 Macomb’s own odds, recorded at PRAIRIE CITY 2S.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 12 | Apr 28 | Apr 15 | Sep 29 | Oct 12 | Oct 24 |
| 32°F | May 2 | Apr 17 | Apr 4 | Oct 7 | Oct 22 | Nov 1 |
| 28°F | Apr 21 | Apr 7 | Mar 22 | Oct 18 | 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 Macomb, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 29 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.
Macomb planting FAQ
When is the last spring frost in Macomb, IL?
On average, the last spring frost in Macomb is around April 17 (50% probability at 32°F, from 1991–2020 NOAA normals). Wait until after this date to set out tender plants like tomatoes and peppers.
When is the first fall frost in Macomb, IL?
Expect Macomb's first fall frost near October 22 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Macomb in?
Macomb 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 Macomb?
Macomb has about 188 frost-free days — a moderate growing season — between the average last spring frost (April 17) and first fall frost (October 22).
When should I plant tomatoes in Macomb?
For Macomb, sow tomatoes indoors about February 20–March 6 and move the seedlings out around April 24, after the last spring frost.
Never miss a window in Macomb
An email when it’s time to start seeds, transplant, and sow — timed to Macomb’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Burlington · 53 km
- Canton · 56 km
- Fort Madison · 59 km
- Galesburg · 59 km
- Quincy · 84 km
- Pekin · 90 km
- Jacksonville · 91 km
- Peoria · 95 km
Frost dates recorded at PRAIRIE CITY 2S, 23 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 Macomb, IL — Frost Dates & Zone 6a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00116970. Retrieved from https://blissgarden.com/illinois/macomb.