Frost dates by ZIP
Last and first frost dates for ZIP 48226 (Detroit, MI)
Detroit (ZIP 48226) has an average last spring frost around May 5 and first fall frost around Oct 15, about 163 frost-free days.
Source: detroit-metro frost station, USDA zone 6b, last updated 2026-06-28. Verify locally before planting high-value crops because microclimates, current weather, and yard exposure can move the safe date.
Detroit (ZIP 48226) has an average last spring frost around May 5 and an average first fall frost around Oct 15, giving about 163 frost-free days.
May 5 last frost
163 frost-free days
Oct 15 first frost