When to plant in Dubuque, IA
USDA Zone 5aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Dubuque, Iowa — all computed from Dubuque's nearest NOAA weather station.
Zone 5a means Dubuque sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
Frost probability
DUBUQUE L&D 11 · 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 Dubuque’s own odds, recorded at DUBUQUE L&D 11.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 14 | May 1 | Apr 16 | Sep 29 | Oct 12 | Oct 24 |
| 32°F | May 4 | Apr 19 | Apr 4 | Oct 7 | Oct 21 | Nov 2 |
| 28°F | Apr 22 | Apr 7 | Mar 25 | Oct 19 | Nov 1 | Nov 14 |
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 Dubuque, 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.
Dubuque planting FAQ
When is the last spring frost in Dubuque, IA?
On average, the last spring frost in Dubuque is around April 19 (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 Dubuque, IA?
The first fall frost in Dubuque typically arrives around October 21 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Dubuque in?
Dubuque 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 Dubuque?
There are roughly 185 frost-free days in Dubuque (a moderate growing season), running from the average last frost around April 19 to the first fall frost near October 21.
When should I plant tomatoes in Dubuque?
In Dubuque, start tomato seeds indoors around February 22–March 8, then transplant seedlings outdoors around April 26 once the danger of frost has passed.
Never miss a window in Dubuque
An email when it’s time to start seeds, transplant, and sow — timed to Dubuque’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Platteville · 32 km
- Clinton · 82 km
- Marion · 88 km
- Monroe · 88 km
- Freeport · 91 km
- Cedar Rapids · 100 km
- Davenport · 105 km
- Bettendorf · 105 km
Frost dates recorded at DUBUQUE L&D 11, 7 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 Dubuque, IA — Frost Dates & Zone 5a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00132364. Retrieved from https://blissgarden.com/iowa/dubuque.