Alto, MI frost dates
Last spring frostApr 30median date
First fall frostOct 14median date
Growing season167 daysfrost-free
Hardiness zone6aZone 6a
How Alto compares
- In 8 years out of 10, the last spring frost in Alto falls between April 16 and May 17, a 31-day window. The first fall frost falls between October 1 and October 28.
- The median last frost is 5 days earlier than the Michigan median of May 5.
- Its 167-day growing season is longer than 65% of the 878 Michigan places with a regular frost season (state median 162 days).
- The last frost is typical for zone 6a, where the median is Apr 29.
- The weather station records an average of 140 nights a year at or below 32°F.
- Compared with Grand Rapids, MI, 23 km away, the last frost here is 6 days earlier than there and the growing season is 10 days longer.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 16 |
| 50% (median) | April 30 |
| 10% (safe for tender plants) | May 17 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 1 |
| 50% (median) | October 14 |
| 90% (late) | October 28 |
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 Alto, MI
Alto, MI frost dates — last frost Apr 30, first frost Oct 14, zone 6a. whenisthelastfrost.com
Crop
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Start indoors: Feb 5 to Feb 19Transplant outside: Apr 2 to Apr 16
Start indoors: Feb 19 to Mar 5Transplant outside: May 14 to May 28
Start indoors: Feb 19 to Mar 5Transplant outside: May 14 to May 28
Start indoors: Mar 5 to Mar 19Transplant outside: May 7 to May 21
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 9 to Apr 23Sow outdoors: Apr 2 to May 7Plant for fall: Aug 19 to Sep 16
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 2 to Apr 16Sow outdoors: Apr 2 to Apr 16Plant for fall: Aug 5 to Aug 26
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 16 to Apr 30Plant for fall: Jul 8 to Jul 29
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 9 to Apr 23Plant for fall: Jul 8 to Jul 29
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 16 to Apr 30Plant for fall: Jul 8 to Jul 29
Start indoors: Mar 19 to Apr 2Transplant outside: May 21 to Jun 4Sow outdoors: May 21 to Jun 4
Start indoors: Mar 19 to Apr 2Transplant outside: May 7 to May 21
Sow outdoors: Mar 19 to Apr 9Plant for fall: Jul 22 to Aug 12
Sow outdoors: Mar 19 to Apr 9Plant for fall: Aug 19 to Sep 9
Sow outdoors: Mar 26 to May 7Plant for fall: Sep 2 to Sep 23
Start indoors: Apr 2 to Apr 9Transplant outside: May 14 to May 21Sow outdoors: May 7 to May 21Plant for fall: Jul 29 to Aug 12
Start indoors: Apr 2 to Apr 9Sow outdoors: May 7 to May 21Plant for fall: Aug 5 to Aug 19
Start indoors: Apr 2 to Apr 9Sow outdoors: May 7 to May 21
Start indoors: Apr 2 to Apr 9Transplant outside: May 14 to May 28
Sow outdoors: Apr 9 to May 7Plant for fall: Jul 22 to Aug 5
Sow outdoors: Apr 9 to May 7Plant for fall: Aug 5 to Aug 19
Sow outdoors: Apr 9 to Apr 30
Sow outdoors: Apr 16 to May 14Plant for fall: Aug 5 to Aug 19
Sow outdoors: Apr 16 to May 7Plant for fall: Aug 19 to Sep 9
Sow outdoors: May 7 to May 28Plant for fall: Jul 29 to Aug 12
Sow outdoors: May 7 to May 21
Transplant outside: May 14 to Jun 4
Plant for fall: Sep 30 to Nov 4
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Alto, MI
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 5 – Feb 19 | Apr 2 – Apr 16 | — | — |
| Peppers | Feb 19 – Mar 5 | May 14 – May 28 | — | — |
| Eggplant | Feb 19 – Mar 5 | May 14 – May 28 | — | — |
| Tomatoes | Mar 5 – Mar 19 | May 7 – May 21 | — | — |
| Lettuce | Mar 5 – Mar 19 | Apr 9 – Apr 23 | Apr 2 – May 7 | Aug 19 – Sep 16 |
| Kale | Mar 5 – Mar 19 | Apr 2 – Apr 16 | Apr 2 – Apr 16 | Aug 5 – Aug 26 |
| Broccoli | Mar 5 – Mar 19 | Apr 16 – Apr 30 | — | Jul 8 – Jul 29 |
| Cabbage | Mar 5 – Mar 19 | Apr 9 – Apr 23 | — | Jul 8 – Jul 29 |
| Cauliflower | Mar 5 – Mar 19 | Apr 16 – Apr 30 | — | Jul 8 – Jul 29 |
| Okra | Mar 19 – Apr 2 | May 21 – Jun 4 | May 21 – Jun 4 | — |
| Basil | Mar 19 – Apr 2 | May 7 – May 21 | — | — |
| Peas | — | — | Mar 19 – Apr 9 | Jul 22 – Aug 12 |
| Spinach | — | — | Mar 19 – Apr 9 | Aug 19 – Sep 9 |
| Radishes | — | — | Mar 26 – May 7 | Sep 2 – Sep 23 |
| Cucumbers | Apr 2 – Apr 9 | May 14 – May 21 | May 7 – May 21 | Jul 29 – Aug 12 |
| Zucchini & Summer Squash | Apr 2 – Apr 9 | — | May 7 – May 21 | Aug 5 – Aug 19 |
| Winter Squash & Pumpkins | Apr 2 – Apr 9 | — | May 7 – May 21 | — |
| Melons & Watermelon | Apr 2 – Apr 9 | May 14 – May 28 | — | — |
| Carrots | — | — | Apr 9 – May 7 | Jul 22 – Aug 5 |
| Beets | — | — | Apr 9 – May 7 | Aug 5 – Aug 19 |
| Potatoes | — | — | Apr 9 – Apr 30 | — |
| Swiss Chard | — | — | Apr 16 – May 14 | Aug 5 – Aug 19 |
| Cilantro | — | — | Apr 16 – May 7 | Aug 19 – Sep 9 |
| Green Beans | — | — | May 7 – May 28 | Jul 29 – Aug 12 |
| Sweet Corn | — | — | May 7 – May 21 | — |
| Sweet Potatoes | — | May 14 – Jun 4 | — | — |
| Garlic | — | — | — | Sep 30 – Nov 4 |
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 Nwsfo Grand Rapids, MI weather station, 12 km away (elevation 774 ft (236 m)).
Frost dates near Alto
- Caledonia Apr 30 · Oct 14
- Freeport May 3 · Oct 12
- Clarksville May 3 · Oct 12
- Middleville May 3 · Oct 12
- Ada Apr 29 · Oct 20
- Lowell Apr 29 · Oct 20
- Moline Apr 30 · Oct 14
- Saranac May 3 · Oct 12
- Hastings May 3 · Oct 12
- Grand Rapids May 6 · Oct 10
Frequently asked questions
When is the last frost in Alto, MI?
The median last spring frost in Alto, MI is April 30. There is still about a 10% chance of frost after May 17, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Alto, MI?
The median first fall frost is October 14, with about a 10% chance of frost before October 1.
How long is the growing season in Alto, MI?
About 167 days between the median last spring frost and first fall frost.
What planting zone is Alto, MI?
Alto, MI is in USDA hardiness zone 6a.