Frost dates for 48107 — Ann Arbor, MI
Last spring frostMay 8median date
First fall frostOct 4median date
Growing season149 daysfrost-free
Hardiness zone6aZone 6a
How Ann Arbor compares
- In 8 years out of 10, the last spring frost in Ann Arbor falls between April 23 and May 26, a 33-day window. The first fall frost falls between September 20 and October 17.
- The median last frost is 3 days later than the Michigan median of May 5.
- Its 149-day growing season is longer than 32% of the 878 Michigan places with a regular frost season (state median 162 days).
- The last frost is 9 days later than the zone 6a median of Apr 29. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 6a chart.
- The weather station records an average of 150 nights a year at or below 32°F.
- Compared with Detroit, MI, 61 km away, the last frost here is 11 days later than there and the growing season is 32 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 23 |
| 50% (median) | May 8 |
| 10% (safe for tender plants) | May 26 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 20 |
| 50% (median) | October 4 |
| 90% (late) | October 17 |
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 Ann Arbor, MI
Frost dates for 48107 — Ann Arbor, MI — last frost May 8, first frost Oct 4, zone 6a. whenisthelastfrost.com
Crop
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Start indoors: Feb 13 to Feb 27Transplant outside: Apr 10 to Apr 24
Start indoors: Feb 27 to Mar 13Transplant outside: May 22 to Jun 5
Start indoors: Feb 27 to Mar 13Transplant outside: May 22 to Jun 5
Start indoors: Mar 13 to Mar 27Transplant outside: May 15 to May 29
Start indoors: Mar 13 to Mar 27Transplant outside: Apr 17 to May 1Sow outdoors: Apr 10 to May 15Plant for fall: Aug 9 to Sep 6
Start indoors: Mar 13 to Mar 27Transplant outside: Apr 10 to Apr 24Sow outdoors: Apr 10 to Apr 24Plant for fall: Jul 26 to Aug 16
Start indoors: Mar 13 to Mar 27Transplant outside: Apr 24 to May 8Plant for fall: Jun 28 to Jul 19
Start indoors: Mar 13 to Mar 27Transplant outside: Apr 17 to May 1Plant for fall: Jun 28 to Jul 19
Start indoors: Mar 13 to Mar 27Transplant outside: Apr 24 to May 8Plant for fall: Jun 28 to Jul 19
Start indoors: Mar 27 to Apr 10Transplant outside: May 29 to Jun 12Sow outdoors: May 29 to Jun 12
Start indoors: Mar 27 to Apr 10Transplant outside: May 15 to May 29
Sow outdoors: Mar 27 to Apr 17Plant for fall: Jul 12 to Aug 2
Sow outdoors: Mar 27 to Apr 17Plant for fall: Aug 9 to Aug 30
Sow outdoors: Apr 3 to May 15Plant for fall: Aug 23 to Sep 13
Start indoors: Apr 10 to Apr 17Transplant outside: May 22 to May 29Sow outdoors: May 15 to May 29Plant for fall: Jul 19 to Aug 2
Start indoors: Apr 10 to Apr 17Sow outdoors: May 15 to May 29Plant for fall: Jul 26 to Aug 9
Start indoors: Apr 10 to Apr 17Sow outdoors: May 15 to May 29
Start indoors: Apr 10 to Apr 17Transplant outside: May 22 to Jun 5
Sow outdoors: Apr 17 to May 15Plant for fall: Jul 12 to Jul 26
Sow outdoors: Apr 17 to May 15Plant for fall: Jul 26 to Aug 9
Sow outdoors: Apr 17 to May 8
Sow outdoors: Apr 24 to May 22Plant for fall: Jul 26 to Aug 9
Sow outdoors: Apr 24 to May 15Plant for fall: Aug 9 to Aug 30
Sow outdoors: May 15 to Jun 5Plant for fall: Jul 19 to Aug 2
Sow outdoors: May 15 to May 29
Transplant outside: May 22 to Jun 12
Plant for fall: Sep 20 to Oct 25
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Ann Arbor, MI
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 13 – Feb 27 | Apr 10 – Apr 24 | — | — |
| Peppers | Feb 27 – Mar 13 | May 22 – Jun 5 | — | — |
| Eggplant | Feb 27 – Mar 13 | May 22 – Jun 5 | — | — |
| Tomatoes | Mar 13 – Mar 27 | May 15 – May 29 | — | — |
| Lettuce | Mar 13 – Mar 27 | Apr 17 – May 1 | Apr 10 – May 15 | Aug 9 – Sep 6 |
| Kale | Mar 13 – Mar 27 | Apr 10 – Apr 24 | Apr 10 – Apr 24 | Jul 26 – Aug 16 |
| Broccoli | Mar 13 – Mar 27 | Apr 24 – May 8 | — | Jun 28 – Jul 19 |
| Cabbage | Mar 13 – Mar 27 | Apr 17 – May 1 | — | Jun 28 – Jul 19 |
| Cauliflower | Mar 13 – Mar 27 | Apr 24 – May 8 | — | Jun 28 – Jul 19 |
| Okra | Mar 27 – Apr 10 | May 29 – Jun 12 | May 29 – Jun 12 | — |
| Basil | Mar 27 – Apr 10 | May 15 – May 29 | — | — |
| Peas | — | — | Mar 27 – Apr 17 | Jul 12 – Aug 2 |
| Spinach | — | — | Mar 27 – Apr 17 | Aug 9 – Aug 30 |
| Radishes | — | — | Apr 3 – May 15 | Aug 23 – Sep 13 |
| Cucumbers | Apr 10 – Apr 17 | May 22 – May 29 | May 15 – May 29 | Jul 19 – Aug 2 |
| Zucchini & Summer Squash | Apr 10 – Apr 17 | — | May 15 – May 29 | Jul 26 – Aug 9 |
| Winter Squash & Pumpkins | Apr 10 – Apr 17 | — | May 15 – May 29 | — |
| Melons & Watermelon | Apr 10 – Apr 17 | May 22 – Jun 5 | — | — |
| Carrots | — | — | Apr 17 – May 15 | Jul 12 – Jul 26 |
| Beets | — | — | Apr 17 – May 15 | Jul 26 – Aug 9 |
| Potatoes | — | — | Apr 17 – May 8 | — |
| Swiss Chard | — | — | Apr 24 – May 22 | Jul 26 – Aug 9 |
| Cilantro | — | — | Apr 24 – May 15 | Aug 9 – Aug 30 |
| Green Beans | — | — | May 15 – Jun 5 | Jul 19 – Aug 2 |
| Sweet Corn | — | — | May 15 – May 29 | — |
| Sweet Potatoes | — | May 22 – Jun 12 | — | — |
| Garlic | — | — | — | Sep 20 – Oct 25 |
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 Ann Arbor Muni Ap, MI weather station, 8 km away (elevation 840 ft (256 m)).
ZIP codes in Ann Arbor: 48103 48104 48105 48106 48107 48108 48109 48113
Frost dates near Ann Arbor
- Saline May 2 · Oct 11
- Bridgewater May 2 · Oct 11
- Dexter Apr 30 · Oct 12
- Chelsea Apr 30 · Oct 12
- Ypsilanti Apr 24 · Oct 24
- Manchester Apr 30 · Oct 14
- Whitmore Lake May 5 · Oct 13
- Hamburg May 5 · Oct 13
Frequently asked questions
When is the last frost in Ann Arbor, MI?
The median last spring frost in Ann Arbor, MI is May 8. There is still about a 10% chance of frost after May 26, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Ann Arbor, MI?
The median first fall frost is October 4, with about a 10% chance of frost before September 20.
How long is the growing season in Ann Arbor, MI?
About 149 days between the median last spring frost and first fall frost.
What planting zone is Ann Arbor, MI?
Ann Arbor, MI is in USDA hardiness zone 6a.