When to plant in St. Peter, MN
USDA Zone 4bHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for St. Peter, Minnesota — all computed from St. Peter's nearest NOAA weather station.
Zone 4b is cold — in St. Peter, most perennials must be fully hardy, and your frost dates set a tight window for tender annual vegetables.
Frost probability
ST PETER · 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 St. Peter’s own odds, recorded at ST PETER.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 23 | May 10 | Apr 30 | Sep 13 | Sep 27 | Oct 8 |
| 32°F | May 14 | May 2 | Apr 19 | Sep 21 | Oct 4 | Oct 16 |
| 28°F | May 5 | Apr 22 | Apr 8 | Sep 28 | Oct 13 | Oct 26 |
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 St. Peter, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 32 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.
St. Peter planting FAQ
When is the last spring frost in St. Peter, MN?
Plan for the last spring frost in St. Peter around May 2 (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 St. Peter, MN?
Expect St. Peter's first fall frost near October 4 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is St. Peter in?
St. Peter is in USDA hardiness zone 4b. In zone 4b, winters are cold — pick cold-hardy varieties and protect tender crops.
How long is the growing season in St. Peter?
There are roughly 155 frost-free days in St. Peter (a moderate growing season), running from the average last frost around May 2 to the first fall frost near October 4.
When should I plant tomatoes in St. Peter?
In St. Peter, start tomato seeds indoors around March 7–March 21, then transplant seedlings outdoors around May 9 once the danger of frost has passed.
Never miss a window in St. Peter
An email when it’s time to start seeds, transplant, and sow — timed to St. Peter’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- North Mankato · 17 km
- Mankato · 18 km
- New Ulm · 40 km
- Faribault · 55 km
- Waconia · 59 km
- Prior Lake · 61 km
- Chaska · 61 km
- Shakopee · 63 km
Frost dates recorded at ST PETER, 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 St. Peter, MN — Frost Dates & Zone 4b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00217405. Retrieved from https://blissgarden.com/minnesota/st-peter.