Median last frost from Apr 27 to May 31 across Michigan
NOAA stations
200
Median last frost, Marquette
May 8
Passed in 9 of 10 years
May 23
Last frost
Last spring frost dates in Michigan
Detroit reaches its median last frost around Apr 21, Benton Harbor on Lake Michigan around May 4, and Marquette, Sault Ste. Marie and Traverse City in the second week of May.
Three dates per station from the NOAA 1991 to 2020 normals. The median is the date half of springs run past. The last column is the date the last 32°F night has passed by in 9 years out of 10, the one to hold tender transplants for.
Sault Ste Marie Sanderson FieldSault Ste Marie Sanderson Field, USW00014847
722 ft
Apr 27
May 9
May 27
Oct 11
Traverse CityTraverse City Cherry Cptl Airport, USW00014850
618 ft
Apr 26
May 12
May 27
Oct 16
Crop chart
When to start seeds in Michigan, spring 2027
Counted back from the median last frost at Marquette, May 8. Pick another station to redraw the chart for it.
Start indoorsHarden offSet outSow outdoorsMedian last frostLast freeze passed in 9 of 10 years
Every crop, counted from a median last frost of May 8
Crop
Start indoors
Set out
Sow outdoors
Frost class
Tomato
Mar 20 to Apr 3
May 15 to May 22
Tender, very tender
Pepper
Mar 13 to Mar 27
May 22 to May 29
Tender, very tender
Eggplant
Mar 13 to Mar 27
May 22 to May 29
Tender, very tender
Basil
Mar 27 to Apr 10
May 22 to May 29
Tender
Celery
Feb 13 to Feb 27
May 8 to May 15
Tender
Cucumber
Apr 17 to Apr 24
May 15 to May 22
May 8 to May 15
Tender
Summer squash
Apr 24 to May 1
May 22 to May 29
May 8 to May 15
Tender
Winter squash
Apr 24 to May 1
May 22 to May 29
May 22 to May 29
Tender, very tender
Pumpkin
Apr 24 to May 1
May 22 to May 29
May 22 to May 29
Tender, very tender
Melon (cantaloupe)
Apr 24 to May 1
May 22 to May 29
Tender, very tender
Watermelon
Apr 17 to May 1
May 22 to May 29
Tender, very tender
Onion (from seed)
Jan 30 to Feb 13
Apr 10 to Apr 17
Hardy
Leek
Jan 30 to Feb 13
Apr 10 to Apr 17
Hardy
Parsley
Feb 6 to Feb 13
Apr 17 to Apr 24
Half-hardy
Broccoli
Feb 27 to Mar 13
Apr 10 to Apr 24
Hardy
Brussels sprouts
Feb 27 to Mar 13
Apr 10 to Apr 24
Hardy
Cabbage
Feb 27 to Mar 13
Apr 10 to Apr 17
Hardy
Cauliflower
Mar 13 to Mar 27
Apr 24 to May 1
Half-hardy
Kale
Feb 27 to Mar 13
Apr 10 to Apr 17
Hardy
Lettuce
Mar 6 to Mar 13
Apr 10 to Apr 17
Hardy
Swiss chard
Mar 13 to Mar 27
Apr 24 to May 1
Apr 10 to Apr 17
Half-hardy
Spinach
Feb 13 to Feb 27
Mar 27 to Apr 17
Apr 10 to Apr 24
Hardy
Peas
Apr 10 to Apr 24
Hardy
Radish
Apr 10 to Apr 24
Hardy
Carrot
Apr 24 to May 8
Half-hardy
Beet
Apr 24 to May 8
Half-hardy
Beans
May 8 to May 15
Tender
Sweet corn
May 8 to May 15
Tender
Tomato seedlings at the seed leaf stage, one to a pot. The University of Minnesota Extension holds off on fertilizer until a seedling has several sets of true leaves, then feeds at quarter strength once a week.“Tomato Seedlings (49768696597)” by Amanda Slater from Coventry, West Midlands, UK, CC BY-SA 2.0
“Rather than relying on a single statewide planting schedule, the new gardening calendars provide month‑by‑month guidance based on local frost dates, soil temperature thresholds and regional growing conditions.”
Setting out a tomato in June at a community garden. Tender crops go out after the last frost, and after a week or two of hardening off outdoors. “Volunteer planting heirloom tomato (4704185147)”, Pacific Southwest Region 5, Public domain
Seed starting questions for Michigan
Count back from the median last frost where you garden. At Marquette (Marquette) that date is May 8, so for spring 2027 onions start indoors Jan 30 to Feb 13, peppers Mar 13 to Mar 27 and tomatoes Mar 20 to Apr 3. Across Michigan's 200 NOAA stations the median last frost runs from Apr 27 to May 31 for the middle 90 percent, so a garden near Vanderbilt 11ENE starts later than one near S Haven.
It depends on the station. The earliest median last spring freeze in Michigan is April 17 at S Haven; the latest is June 7 at Vanderbilt 11ENE. A median is a coin flip: at Marquette the last 32°F freeze comes after May 8 in half of years, and has passed by May 23 in 9 of 10 years (NOAA 1991 to 2020 normals).
UNH Extension sets tomatoes out 1 to 2 weeks after the last frost, which at Marquette is May 15 to May 22 in 2027. Tomatoes are frost tender, so the date to watch is May 23, when 9 of 10 springs at Marquette have had their last 32°F night. Hardening off starts two weeks before setting out (May 1 to May 15).
Michigan State University Extension's Lower Peninsula and Upper Peninsula Michigan Gardening Calendars (announced in MSUToday) puts it this way: "Rather than relying on a single statewide planting schedule, the new gardening calendars provide month‑by‑month guidance based on local frost dates, soil temperature thresholds and regional growing conditions." The guide is linked below with the date it was read (September 21, 2026).
UNH Extension gives 8 to 10 weeks from seed to transplant for both, and sets peppers out 2 weeks after the last frost and eggplant 2 to 3 weeks after, so the sowing date is 6 to 8 weeks before the median last frost. At Marquette that is Mar 13 to Mar 27 for peppers.
About two weeks. University of Missouri Extension: "Hardening should be started about two weeks before planting in the garden." University of Minnesota Extension adds that seedlings should go out on a cloudy day or in the late afternoon.
Detroit reaches its median last frost around Apr 21, Benton Harbor on Lake Michigan around May 4, and Marquette, Sault Ste. Marie and Traverse City in the second week of May. Each station carries its own dates: Detroit Apr 21 and Traverse City May 12 at the median.
