Ishpeming, MI frost dates
Last spring frostMay 26median date
First fall frostSep 25median date
Growing season122 daysfrost-free
Hardiness zone4bZone 4b
How Ishpeming compares
- In 8 years out of 10, the last spring frost in Ishpeming falls between May 10 and June 8, a 29-day window. The first fall frost falls between September 4 and October 9.
- The median last frost is 21 days later than the Michigan median of May 5.
- Its 122-day growing season is longer than 5% of the 878 Michigan places with a regular frost season (state median 162 days).
- The last frost is 18 days later than the zone 4b median of May 8. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 4b chart.
- The weather station records an average of 191 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 10 |
| 50% (median) | May 26 |
| 10% (safe for tender plants) | June 8 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 4 |
| 50% (median) | September 25 |
| 90% (late) | October 9 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Ishpeming, MI
Ishpeming, MI frost dates — last frost May 26, first frost Sep 25, zone 4b. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Mar 3 to Mar 17Transplant outside: Apr 28 to May 12
Start indoors: Mar 17 to Mar 31Transplant outside: Jun 9 to Jun 23
Start indoors: Mar 17 to Mar 31Transplant outside: Jun 9 to Jun 23
Start indoors: Mar 31 to Apr 14Transplant outside: Jun 2 to Jun 16
Start indoors: Mar 31 to Apr 14Transplant outside: May 5 to May 19Sow outdoors: Apr 28 to Jun 2Plant for fall: Jul 31 to Aug 28
Start indoors: Mar 31 to Apr 14Transplant outside: Apr 28 to May 12Sow outdoors: Apr 28 to May 12Plant for fall: Jul 17 to Aug 7
Start indoors: Mar 31 to Apr 14Transplant outside: May 12 to May 26Plant for fall: Jun 19 to Jul 10
Start indoors: Mar 31 to Apr 14Transplant outside: May 5 to May 19Plant for fall: Jun 19 to Jul 10
Start indoors: Mar 31 to Apr 14Transplant outside: May 12 to May 26Plant for fall: Jun 19 to Jul 10
Start indoors: Apr 14 to Apr 28Transplant outside: Jun 16 to Jun 30Sow outdoors: Jun 16 to Jun 30
Start indoors: Apr 14 to Apr 28Transplant outside: Jun 2 to Jun 16
Sow outdoors: Apr 14 to May 5Plant for fall: Jul 3 to Jul 24
Sow outdoors: Apr 14 to May 5Plant for fall: Jul 31 to Aug 21
Sow outdoors: Apr 21 to Jun 2Plant for fall: Aug 14 to Sep 4
Start indoors: Apr 28 to May 5Transplant outside: Jun 9 to Jun 16Sow outdoors: Jun 2 to Jun 16Plant for fall: Jul 10 to Jul 24
Start indoors: Apr 28 to May 5Sow outdoors: Jun 2 to Jun 16Plant for fall: Jul 17 to Jul 31
Start indoors: Apr 28 to May 5Sow outdoors: Jun 2 to Jun 16
Start indoors: Apr 28 to May 5Transplant outside: Jun 9 to Jun 23
Sow outdoors: May 5 to Jun 2Plant for fall: Jul 3 to Jul 17
Sow outdoors: May 5 to Jun 2Plant for fall: Jul 17 to Jul 31
Sow outdoors: May 5 to May 26
Sow outdoors: May 12 to Jun 9Plant for fall: Jul 17 to Jul 31
Sow outdoors: May 12 to Jun 2Plant for fall: Jul 31 to Aug 21
Sow outdoors: Jun 2 to Jun 23Plant for fall: Jul 10 to Jul 24
Sow outdoors: Jun 2 to Jun 16
Transplant outside: Jun 9 to Jun 30
Plant for fall: Sep 11 to Oct 16
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Ishpeming, MI
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 3 – Mar 17 | Apr 28 – May 12 | — | — |
| Peppers | Mar 17 – Mar 31 | Jun 9 – Jun 23 | — | — |
| Eggplant | Mar 17 – Mar 31 | Jun 9 – Jun 23 | — | — |
| Tomatoes | Mar 31 – Apr 14 | Jun 2 – Jun 16 | — | — |
| Lettuce | Mar 31 – Apr 14 | May 5 – May 19 | Apr 28 – Jun 2 | Jul 31 – Aug 28 |
| Kale | Mar 31 – Apr 14 | Apr 28 – May 12 | Apr 28 – May 12 | Jul 17 – Aug 7 |
| Broccoli | Mar 31 – Apr 14 | May 12 – May 26 | — | Jun 19 – Jul 10 |
| Cabbage | Mar 31 – Apr 14 | May 5 – May 19 | — | Jun 19 – Jul 10 |
| Cauliflower | Mar 31 – Apr 14 | May 12 – May 26 | — | Jun 19 – Jul 10 |
| Okra | Apr 14 – Apr 28 | Jun 16 – Jun 30 | Jun 16 – Jun 30 | — |
| Basil | Apr 14 – Apr 28 | Jun 2 – Jun 16 | — | — |
| Peas | — | — | Apr 14 – May 5 | Jul 3 – Jul 24 |
| Spinach | — | — | Apr 14 – May 5 | Jul 31 – Aug 21 |
| Radishes | — | — | Apr 21 – Jun 2 | Aug 14 – Sep 4 |
| Cucumbers | Apr 28 – May 5 | Jun 9 – Jun 16 | Jun 2 – Jun 16 | Jul 10 – Jul 24 |
| Zucchini & Summer Squash | Apr 28 – May 5 | — | Jun 2 – Jun 16 | Jul 17 – Jul 31 |
| Winter Squash & Pumpkins | Apr 28 – May 5 | — | Jun 2 – Jun 16 | — |
| Melons & Watermelon | Apr 28 – May 5 | Jun 9 – Jun 23 | — | — |
| Carrots | — | — | May 5 – Jun 2 | Jul 3 – Jul 17 |
| Beets | — | — | May 5 – Jun 2 | Jul 17 – Jul 31 |
| Potatoes | — | — | May 5 – May 26 | — |
| Swiss Chard | — | — | May 12 – Jun 9 | Jul 17 – Jul 31 |
| Cilantro | — | — | May 12 – Jun 2 | Jul 31 – Aug 21 |
| Green Beans | — | — | Jun 2 – Jun 23 | Jul 10 – Jul 24 |
| Sweet Corn | — | — | Jun 2 – Jun 16 | — |
| Sweet Potatoes | — | Jun 9 – Jun 30 | — | — |
| Garlic | — | — | — | Sep 11 – Oct 16 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Ishpeming Wwtp, MI weather station, 6 km away (elevation 1,407 ft (429 m)).
Frost dates near Ishpeming
- Champion Jun 5 · Sep 10
- Palmer May 22 · Sep 29
- Negaunee May 22 · Sep 29
- National Mine May 22 · Sep 29
- Republic frost any month
- Gwinn May 13 · Oct 2
- Marquette May 8 · Oct 21
- Michigamme frost any month
- Little Lake May 13 · Oct 2
- Ralph May 13 · Oct 2
Frequently asked questions
When is the last frost in Ishpeming, MI?
The median last spring frost in Ishpeming, MI is May 26. There is still about a 10% chance of frost after June 8, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Ishpeming, MI?
The median first fall frost is September 25, with about a 10% chance of frost before September 4.
How long is the growing season in Ishpeming, MI?
About 122 days between the median last spring frost and first fall frost.
What planting zone is Ishpeming, MI?
Ishpeming, MI is in USDA hardiness zone 4b.