When to plant in Marion, IA
USDA Zone 5aMarion, Iowa frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
In zone 5a, Marion gardeners can grow many hardy perennials, while the last and first frost still dictate the annual vegetable calendar.
Frost probability
CEDAR RAPIDS #1 · 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 CEDAR RAPIDS #1.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 22 | May 7 | Apr 23 | Sep 19 | Oct 2 | Oct 14 |
| 32°F | May 13 | Apr 28 | Apr 14 | Sep 29 | Oct 12 | Oct 25 |
| 28°F | May 2 | Apr 17 | Apr 4 | Oct 8 | Oct 22 | Nov 1 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 20Full-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 24 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, IA?
Plan for the last spring frost in Marion around April 28 (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 Marion, IA?
In Marion, the first 32°F freeze of fall lands around October 12 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Marion in?
Marion is in USDA hardiness zone 5a. In zone 5a, winters are cold — pick cold-hardy varieties and protect tender crops.
How long is the growing season in Marion?
Marion has about 167 frost-free days — a moderate growing season — between the average last spring frost (April 28) and first fall frost (October 12).
When should I plant tomatoes in Marion?
For Marion, sow tomatoes indoors about March 3–March 17 and move the seedlings out around May 5, 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- Cedar Rapids · 12 km
- North Liberty · 34 km
- Coralville · 38 km
- Iowa City · 43 km
- Waterloo · 80 km
- Muscatine · 82 km
- Dubuque · 88 km
- Cedar Falls · 89 km
Frost dates recorded at CEDAR RAPIDS #1, 1 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, IA — Frost Dates & Zone 5a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00131319. Retrieved from https://blissgarden.com/iowa/marion.