Last spring frost
May 11
Frost Dates for Hendrum, MN
First fall frost
Sep 27
Growing season
137 days
Hardiness zone
4a
In an average year around Hendrum, MN, the last spring frost (32°F) is about May 11 and the first fall frost is about Sep 27, giving roughly a 137-day growing season. To be safe most years, wait until Apr 30 before setting out tender plants.
Last spring frost
Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Jun 3 | May 22 | May 9 |
| Freeze (32°F) | May 25 | May 11 | Apr 30 |
| Hard (28°F) | May 18 | May 2 | Apr 18 |
| Severe (24°F) | May 7 | Apr 22 | Apr 7 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jun 3 | May 31 | May 27 | May 25 | May 22 | May 19 | May 16 | May 13 | May 9 |
| 32°F | May 25 | May 20 | May 17 | May 14 | May 11 | May 8 | May 6 | May 3 | Apr 30 |
| 28°F | May 18 | May 13 | May 8 | May 5 | May 2 | Apr 30 | Apr 27 | Apr 24 | Apr 18 |
| 24°F | May 7 | May 2 | Apr 29 | Apr 25 | Apr 22 | Apr 19 | Apr 16 | Apr 12 | Apr 7 |
| 20°F | Apr 27 | Apr 21 | Apr 18 | Apr 15 | Apr 12 | Apr 9 | Apr 6 | Apr 4 | Mar 31 |
| 16°F | Apr 18 | Apr 13 | Apr 9 | Apr 7 | Apr 4 | Apr 3 | Apr 1 | Mar 27 | Mar 22 |
First fall frost
Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Sep 2 | Sep 17 | Sep 29 |
| Freeze (32°F) | Sep 14 | Sep 27 | Oct 9 |
| Hard (28°F) | Sep 23 | Oct 6 | Oct 21 |
| Severe (24°F) | Oct 1 | Oct 18 | Nov 2 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 2 | Sep 8 | Sep 12 | Sep 15 | Sep 17 | Sep 20 | Sep 22 | Sep 25 | Sep 29 |
| 32°F | Sep 14 | Sep 19 | Sep 22 | Sep 25 | Sep 27 | Sep 30 | Oct 2 | Oct 5 | Oct 9 |
| 28°F | Sep 23 | Sep 27 | Oct 1 | Oct 3 | Oct 6 | Oct 9 | Oct 13 | Oct 17 | Oct 21 |
| 24°F | Oct 1 | Oct 6 | Oct 10 | Oct 14 | Oct 18 | Oct 22 | Oct 25 | Oct 28 | Nov 2 |
| 20°F | Oct 11 | Oct 19 | Oct 23 | Oct 27 | Oct 30 | Nov 1 | Nov 3 | Nov 6 | Nov 11 |
| 16°F | Oct 25 | Oct 30 | Nov 1 | Nov 3 | Nov 5 | Nov 8 | Nov 11 | Nov 14 | Nov 20 |
Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.
Where this data comes from
@endif These dates are computed from the nearest official weather station with long-term records: Ada, Mn, about 10.8 miles away@if(!empty($station['elevation_ft'])), at 907 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.
How we calculate these dates
Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.
Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.
Frequently asked questions
When is the last frost in Hendrum, MN?
On average, the last spring frost (32°F) around Hendrum, MN is about May 11. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 30.
When is the first frost in the fall?
The first fall frost around Hendrum, MN typically arrives about Sep 27. Count back by a crop's days to maturity to find the latest date you can plant it.
When can I plant tomatoes and other tender crops?
Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around May 11 on average, or Apr 30 to be safe most years.
How long is the growing season here?
The frost-free growing season (between the last spring and first fall 32°F frost) is about 137 days in a typical year.
Are these dates a forecast for this year?
No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.
Local weather for 56550 Planting calendar → Minnesota frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026