Last spring frost
May 2
Frost Dates for Frankfort, MI
First fall frost
Oct 26
Growing season
175 days
Hardiness zone
6b
In an average year around Frankfort, MI, the last spring frost (32°F) is about May 2 and the first fall frost is about Oct 26, giving roughly a 175-day growing season. To be safe most years, wait until Apr 19 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) | May 31 | May 16 | Apr 30 |
| Freeze (32°F) | May 20 | May 2 | Apr 19 |
| Hard (28°F) | May 6 | Apr 20 | Apr 4 |
| Severe (24°F) | Apr 21 | Apr 7 | Mar 24 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 31 | May 27 | May 23 | May 20 | May 16 | May 13 | May 9 | May 4 | Apr 30 |
| 32°F | May 20 | May 14 | May 9 | May 6 | May 2 | Apr 30 | Apr 27 | Apr 23 | Apr 19 |
| 28°F | May 6 | Apr 30 | Apr 27 | Apr 23 | Apr 20 | Apr 17 | Apr 13 | Apr 9 | Apr 4 |
| 24°F | Apr 21 | Apr 16 | Apr 13 | Apr 9 | Apr 7 | Apr 4 | Apr 2 | Mar 30 | Mar 24 |
| 20°F | Apr 10 | Apr 5 | Apr 2 | Mar 31 | Mar 29 | Mar 26 | Mar 21 | Mar 17 | Mar 13 |
| 16°F | Apr 2 | Mar 29 | Mar 26 | Mar 22 | Mar 18 | Mar 15 | Mar 12 | Mar 7 | Feb 28 |
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 26 | Oct 12 | Oct 28 |
| Freeze (32°F) | Oct 7 | Oct 26 | Nov 9 |
| Hard (28°F) | Oct 24 | Nov 7 | Nov 23 |
| Severe (24°F) | Nov 4 | Nov 19 | Dec 4 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 26 | Oct 1 | Oct 5 | Oct 8 | Oct 12 | Oct 15 | Oct 18 | Oct 23 | Oct 28 |
| 32°F | Oct 7 | Oct 14 | Oct 19 | Oct 22 | Oct 26 | Oct 30 | Nov 1 | Nov 4 | Nov 9 |
| 28°F | Oct 24 | Oct 29 | Nov 1 | Nov 4 | Nov 7 | Nov 9 | Nov 13 | Nov 17 | Nov 23 |
| 24°F | Nov 4 | Nov 8 | Nov 12 | Nov 16 | Nov 19 | Nov 22 | Nov 26 | Nov 30 | Dec 4 |
| 20°F | Nov 14 | Nov 19 | Nov 23 | Nov 27 | Nov 30 | Dec 3 | Dec 6 | Dec 12 | Dec 18 |
| 16°F | Nov 25 | Nov 30 | Dec 4 | Dec 7 | Dec 12 | Dec 16 | Dec 20 | Dec 24 | Jan 1 |
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: Frankfort 2Ne, Mi, about 1.8 miles away@if(!empty($station['elevation_ft'])), at 948 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 Frankfort, MI?
On average, the last spring frost (32°F) around Frankfort, MI is about May 2. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 19.
When is the first frost in the fall?
The first fall frost around Frankfort, MI typically arrives about Oct 26. 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 2 on average, or Apr 19 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 175 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 49635 Planting calendar → Michigan frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026