When to plant in Storm Lake, IA
USDA Zone 5aEverything below — frost dates, hardiness zone, and what to plant when in Storm Lake, Iowa — is derived from the closest NOAA station with complete climate normals.
Zone 5a means Storm Lake sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
Frost probability
STORM LAKE · 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 Storm Lake’s own odds, recorded at STORM LAKE.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 16 | May 4 | Apr 22 | Sep 21 | Oct 3 | Oct 15 |
| 32°F | May 7 | Apr 25 | Apr 11 | Oct 1 | Oct 13 | Oct 25 |
| 28°F | Apr 29 | Apr 15 | Apr 2 | Oct 11 | Oct 23 | Nov 5 |
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 Storm Lake, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 31 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.
Storm Lake planting FAQ
When is the last spring frost in Storm Lake, IA?
Plan for the last spring frost in Storm Lake around April 25 (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 Storm Lake, IA?
The first fall frost in Storm Lake typically arrives around October 13 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Storm Lake in?
Storm Lake 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 Storm Lake?
There are roughly 171 frost-free days in Storm Lake (a moderate growing season), running from the average last frost around April 25 to the first fall frost near October 13.
When should I plant tomatoes in Storm Lake?
In Storm Lake, start tomato seeds indoors around February 28–March 14, then transplant seedlings outdoors around May 2 once the danger of frost has passed.
Never miss a window in Storm Lake
An email when it’s time to start seeds, transplant, and sow — timed to Storm Lake’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Spencer · 56 km
- Carroll · 69 km
- Le Mars · 81 km
- Fort Dodge · 85 km
- Sioux City · 99 km
- South Sioux City · 102 km
- Worthington · 114 km
- Fairmont · 126 km
Frost dates recorded at STORM LAKE, 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 Storm Lake, IA — Frost Dates & Zone 5a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00137979. Retrieved from https://blissgarden.com/iowa/storm-lake.