When to plant in Marion, IL
USDA Zone 7aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Marion, Illinois — all computed from Marion's nearest NOAA weather station.
These dates come from a station roughly 20 km away, the closest with full normals; terrain around Marion (elevation, water, pavement) can move your real frost dates a few days either way. In zone 7a, Marion supports a wide range of perennials year-round; the frost dates above are what set your annual vegetable timing.
Frost probability
CARBONDALE SEWAGE PLT · 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 Marion’s own odds, recorded at CARBONDALE SEWAGE PLT.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 5 | Apr 22 | Apr 5 | Sep 30 | Oct 13 | Oct 25 |
| 32°F | Apr 25 | Apr 9 | Mar 25 | Oct 10 | Oct 22 | Nov 2 |
| 28°F | Apr 14 | Mar 29 | Mar 11 | Oct 19 | Nov 1 | Nov 18 |
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 Marion, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 33 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.
Marion planting FAQ
When is the last spring frost in Marion, IL?
On average, the last spring frost in Marion is around April 9 (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 Marion, IL?
Expect Marion'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 Marion in?
Marion is in USDA hardiness zone 7a. In zone 7a, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Marion?
Marion has about 196 frost-free days — a moderate growing season — between the average last spring frost (April 9) and first fall frost (October 22).
When should I plant tomatoes in Marion?
For Marion, sow tomatoes indoors about February 12–February 26 and move the seedlings out around April 16, after the last spring frost.
Never miss a window in Marion
An email when it’s time to start seeds, transplant, and sow — timed to Marion’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Herrin · 11 km
- Carbondale · 25 km
- Mount Vernon · 64 km
- Cape Girardeau · 72 km
- Jackson · 74 km
- Paducah · 78 km
- Centralia · 89 km
- Sikeston · 111 km
Frost dates recorded at CARBONDALE SEWAGE PLT, 20 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 Marion, IL — Frost Dates & Zone 7a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00111265. Retrieved from https://blissgarden.com/illinois/marion.