Frost Dates for Detroit, MI 48228

Last spring frost April 26 · First fall frost October 17 · 174 frost-free days · USDA Zone 6b

Frost probability for 48228

Frost10%50%90%
Spring (last frost)May 10April 26April 11
Fall (first frost)October 4October 17October 30

Dates come from NOAA 1971–2000 freeze probabilities at the nearest reporting station (16.7 km away); the 50% date is the median year.

Frost dates by ZIP code in Detroit, MI

ZIPLast spring frost (50%)First fall frost (50%)Zone
48228April 26October 176b
48219April 26October 176b
48235April 26October 176b
48221April 26October 176b
48227April 26October 176b
48224May 1October 206b
48205May 1October 206b
48234May 1October 206b
48209April 26October 176b
48210April 26October 176b
48238April 26October 176b
48223April 26October 176b
48207May 1October 206b
48204April 26October 176b
48213May 1October 206b
48214May 1October 206b
48202April 26October 176b
48206April 26October 176b
48201April 26October 176b
48215May 1October 206b
48208April 26October 176b
48226April 26October 176b
48217April 26October 176b
48216April 26October 176b
48211May 1October 206b
48233April 26October 176b
48242April 26October 176b
48243April 26October 176b

Month by month in Detroit

MonthWhat to do
JanuaryPlan your garden layout and order seeds. Research varieties suited to your frost dates.
FebruaryStart peppers and eggplant indoors 8–10 weeks before your last frost (around April 26). Start tomatoes about two weeks later, 6–8 weeks before last frost.
MarchStart herbs, basil, and squash indoors (4–6 weeks before frost). Direct sow peas, spinach, and lettuce if soil is workable.
AprilLast frost around April 26. Transplant cold-hardy crops (broccoli, kale, cabbage). Harden off tomato and pepper seedlings.
MayFrost has passed. Transplant tomatoes, peppers, and basil outdoors. Direct sow beans, cucumbers, squash, and zucchini.
JuneSuccession plant lettuce and greens. Keep beds weeded and watered consistently.
JulyHarvest regularly to encourage production. Monitor for pests and disease.
AugustMidsummer: harvest beans, zucchini, cucumbers. Start brassica seeds indoors for fall.
SeptemberFirst fall frost approaching (around October 17). Transplant fall brassicas. Sow spinach, arugula, and radishes.
OctoberFirst frost around October 17. Harvest tomatoes and peppers before frost. Cover cold-hardy crops with row covers to extend the season.
NovemberHarvest remaining cold-hardy crops: kale, carrots, and beets. Plant garlic bulbs for next year.
DecemberClean up spent plants. Add compost to beds. Rest, review, and plan next year's garden.

What grows in a 174-day season

Frequently Asked Questions

What is the last frost date for Detroit, MI (ZIP 48228)?

The median last spring frost date for Detroit, MI (ZIP code 48228) is around April 26. This is the 50th-percentile date — meaning half of all years see frost end before this date. Use the 10% and 90% dates to understand the full range of risk in your area.

What is the first fall frost date in Detroit, MI?

The median first fall frost date for Detroit, MI is around October 17. Plan to harvest or protect frost-sensitive crops like tomatoes and peppers at least a week before this date to avoid losses.

How long is the growing season in Detroit, MI?

The frost-free growing season in Detroit is about 174 days. This window — from your last spring frost to your first fall frost — is when warm-season vegetables thrive. Cold-hardy crops like kale, spinach, and peas can extend your season by weeks on either side.

What USDA hardiness zone is Detroit, MI?

Based on frost date patterns, Detroit falls approximately in 6b. USDA hardiness zones are determined by average annual minimum winter temperatures and guide both plant selection and planting timing for your location.

When should I start tomatoes indoors in Detroit, MI?

Start tomato seeds indoors 6–8 weeks before your last frost date (around April 26). For Detroit, that's roughly March 1 to March 15. Transplant outdoors 1–2 weeks after your last frost.

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