Last spring frost
May 14
Frost Dates for Ravenna, MI
First fall frost
Sep 29
Growing season
135 days
Hardiness zone
6a
In an average year around Ravenna, MI, the last spring frost (32°F) is about May 14 and the first fall frost is about Sep 29, giving roughly a 135-day growing season. To be safe most years, wait until Apr 29 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 13 | May 29 | May 9 |
| Freeze (32°F) | May 31 | May 14 | Apr 29 |
| Hard (28°F) | May 19 | May 2 | Apr 20 |
| Severe (24°F) | May 8 | Apr 23 | Apr 10 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jun 13 | Jun 7 | Jun 3 | May 31 | May 29 | May 25 | May 22 | May 17 | May 9 |
| 32°F | May 31 | May 26 | May 22 | May 18 | May 14 | May 10 | May 6 | May 3 | Apr 29 |
| 28°F | May 19 | May 14 | May 9 | May 5 | May 2 | Apr 30 | Apr 28 | Apr 24 | Apr 20 |
| 24°F | May 8 | May 3 | Apr 30 | Apr 26 | Apr 23 | Apr 20 | Apr 18 | Apr 14 | Apr 10 |
| 20°F | Apr 28 | Apr 21 | Apr 18 | Apr 15 | Apr 12 | Apr 9 | Apr 5 | Apr 2 | Mar 30 |
| 16°F | Apr 16 | Apr 11 | Apr 7 | Apr 4 | Apr 1 | Mar 30 | Mar 26 | Mar 22 | Mar 16 |
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) | Aug 30 | Sep 18 | Oct 2 |
| Freeze (32°F) | Sep 14 | Sep 29 | Oct 12 |
| Hard (28°F) | Sep 24 | Oct 8 | Oct 23 |
| Severe (24°F) | Oct 4 | Oct 22 | Nov 7 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Aug 30 | Sep 5 | Sep 10 | Sep 14 | Sep 18 | Sep 21 | Sep 24 | Sep 28 | Oct 2 |
| 32°F | Sep 14 | Sep 19 | Sep 23 | Sep 26 | Sep 29 | Oct 2 | Oct 4 | Oct 7 | Oct 12 |
| 28°F | Sep 24 | Sep 29 | Oct 3 | Oct 5 | Oct 8 | Oct 12 | Oct 14 | Oct 18 | Oct 23 |
| 24°F | Oct 4 | Oct 10 | Oct 15 | Oct 19 | Oct 22 | Oct 26 | Oct 29 | Nov 1 | Nov 7 |
| 20°F | Oct 21 | Oct 27 | Nov 1 | Nov 3 | Nov 6 | Nov 11 | Nov 15 | Nov 21 | Nov 27 |
| 16°F | Nov 5 | Nov 11 | Nov 16 | Nov 20 | Nov 23 | Nov 28 | Dec 1 | Dec 6 | Dec 13 |
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: Kent City 2 Sw, Mi, about 9.9 miles away@if(!empty($station['elevation_ft'])), at 840 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 Ravenna, MI?
On average, the last spring frost (32°F) around Ravenna, MI is about May 14. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 29.
When is the first frost in the fall?
The first fall frost around Ravenna, MI typically arrives about Sep 29. 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 14 on average, or Apr 29 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 135 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 49451 Planting calendar → Michigan frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026