When to plant in Carroll, IA
USDA Zone 5aEverything below — frost dates, hardiness zone, and what to plant when in Carroll, Iowa — is derived from the closest NOAA station with complete climate normals.
In zone 5a, Carroll gardeners can grow many hardy perennials, while the last and first frost still dictate the annual vegetable calendar.
The average first fall frost in Carroll is now 7 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
CARROLL · 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 Carroll’s own odds, recorded at CARROLL.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 17 | May 6 | Apr 23 | Sep 17 | Sep 30 | Oct 14 |
| 32°F | May 8 | Apr 27 | Apr 14 | Sep 25 | Oct 10 | Oct 24 |
| 28°F | Apr 29 | Apr 16 | Apr 3 | Oct 5 | Oct 21 | Nov 3 |
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 Carroll, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 39 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.
Carroll planting FAQ
When is the last spring frost in Carroll, IA?
Carroll's average last spring frost falls near April 27 — 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 Carroll, IA?
In Carroll, the first 32°F freeze of fall lands around October 10 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Carroll in?
Carroll 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 Carroll?
Carroll has about 166 frost-free days — a moderate growing season — between the average last spring frost (April 27) and first fall frost (October 10).
When should I plant tomatoes in Carroll?
For Carroll, sow tomatoes indoors about March 2–March 16 and move the seedlings out around May 4, after the last spring frost.
Never miss a window in Carroll
An email when it’s time to start seeds, transplant, and sow — timed to Carroll’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Storm Lake · 69 km
- Fort Dodge · 75 km
- Boone · 82 km
- Waukee · 97 km
- Grimes · 98 km
- Clive · 102 km
- Urbandale · 102 km
- Ames · 103 km
Frost dates recorded at CARROLL, 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 Carroll, IA — Frost Dates & Zone 5a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00131233. Retrieved from https://blissgarden.com/iowa/carroll.