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Frost Dates in Minnesota
First and last frost dates across Minnesota, computed from 106 NOAA weather stations (1991–2020 climate normals). Your exact date depends on your city and microclimate — use the ZIP lookup on the main tool for a station-specific answer.
Last spring frost
May 6
statewide median · range Apr 15–Jun 5
First fall frost
Oct 2
statewide median · range Sep 8–Oct 28
Growing season
148 days
median · range 93–194
Stations used
106
NOAA 1991–2020 normals
Frost dates by city
Median dates from the nearest NOAA station to each city. The "cautious" date is the 10% spring value — planting after it means only a ~10% chance of a later frost.
| City | Nearest station | Last spring frost | First fall frost | Growing season | Safe transplant |
|---|---|---|---|---|---|
| Minneapolis | New Hope · 6 mi | Apr 29 (cautious: May 12) | Oct 12 | 163 days | May 13 |
| St. Paul | St Paul Dwtn Ap · 2 mi | Apr 24 (cautious: May 10) | Oct 16 | 174 days | May 8 |
| Duluth | Superior (WI) · 4 mi | May 6 (cautious: May 25) | Oct 9 | 154 days | May 20 |
How frost varies across Minnesota
Spring frost timing spans about 51 days across the state. La Crescent Dam 7 in southeastern Minnesota typically sees its last spring frost around April 15, while Hibbing Chisholm Hibbing in northern Minnesota doesn't clear frost until about June 5. Within any city, low spots and valleys run colder than the station average; areas near buildings and pavement run warmer.
When to plant in Minnesota
As a rule of thumb, cool-season crops (lettuce, peas, spinach) can go in 2–4 weeks before your last spring frost; warm-season transplants (tomatoes, peppers) should wait about 2 weeks after it — around May 20 for the statewide median. Check your city's row above rather than the statewide median: a 51-day statewide spread makes the city-level date the one that matters.
These are climate normals (what's typical), not forecasts. For the current year, watch the 10-day forecast around your planting date.
How this is computed
Statewide medians are the median of the 106 NOAA stations' median frost dates — half the stations run earlier, half later. City rows use the nearest station with 30-year freeze records. Dates are 32°F freeze probabilities from NOAA NCEI 1991–2020 U.S. Climate Normals; nothing is estimated or interpolated.
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Frequently asked questions
When is the last frost date in Minnesota?
The statewide median last spring frost is May 6, but it ranges from April 15 to June 5 depending on where in the state you are. Use your city's row in the table above, or the ZIP lookup on the main tool, for a station-specific date.
When can I plant tomatoes outside in Minnesota?
Warm-season transplants like tomatoes should wait about two weeks after your last spring frost — around May 20 for the statewide median. Your city may differ by weeks; check the "safe transplant" column in the city table.
How long is the growing season in Minnesota?
The median growing season across 106 NOAA stations is 148 days, ranging from 93 to 194 days by location.
Why do frost dates vary so much within Minnesota?
Frost timing follows latitude, elevation, and local terrain. Across Minnesota, last spring frost dates span about 51 days — from around April 15 near La Crescent Dam 7 to June 5 near Hibbing Chisholm Hibbing. Microclimates (low spots, valleys, urban heat) shift dates further at the garden level.
Where does this data come from?
All frost dates are computed from the NOAA National Centers for Environmental Information 1991–2020 U.S. Climate Normals freeze data (public domain), using each station's 32°F freeze probability statistics. No dates are estimated or interpolated.