Ann Arbor, MI Frost Dates
Average frost dates, USDA hardiness zone, and growing season length for Ann Arbor, Michigan.
Gardening in Ann Arbor
A college town with a food obsession. Ann Arbor's combination of University of Michigan intellectual culture and Zingerman's food empire has created a city where growing, sourcing, and eating local food is practically a contact sport.
The Huron River valley provides fertile growing ground, and Ann Arbor's southern Michigan location gives it a 176-day growing season — slightly longer than northern Michigan cities. The glacial soils are variable: sandy outwash in some areas, heavy clay in others.
Zingerman's didn't just build a food business — they inspired a food culture. The Ann Arbor Farmers Market at Kerrytown is where that culture meets the soil. The Leslie Science Center and dozens of school gardens make food growing part of the city's educational DNA.
What This Means for Ann Arbor Gardeners
The average last spring frost in Ann Arbor is around April 22, and the average first fall frost arrives around October 15. That gives you approximately 176 frost-free days to work with.
A solid, workable season. Most standard vegetable varieties have enough time to mature, though the longest-season crops (like sweet potatoes at 90+ days or large watermelons at 85+ days) need to be started early and chosen carefully. Indoor seed starting isn't optional — it's how you buy the extra weeks that make the difference between a good harvest and a great one.
These dates are based on NOAA 30-year Climate Normal data for the Ann Arbor area. Your actual frost dates could shift 2-3 weeks in either direction in any given year. Learn more about our data sources.
What to Grow in Ann Arbor
Ann Arbor's 176-day season gives you plenty of time for most vegetables with good planning. Start warm-season crops indoors to maximize your window. Cool-season crops thrive in your spring and fall shoulder seasons. Recommended starting points: tomatoes, peppers, lettuce, carrots, beans, broccoli, garlic, and basil.
See the full Michigan planting guide for all 40 plants: Michigan Planting Calendar. Or enter your zip code for exact planting dates personalized to Ann Arbor.
More About Zone 6A
Ann Arbor is in USDA Hardiness Zone 6A, which means average annual extreme minimum temperatures between -10°F to -5°F. View the full Zone 6A planting guide.
See the complete planting calendar for Michigan: Michigan Planting Calendar.
Other Cities in Michigan
Frequently Asked Questions
These dates are based on NOAA's 30-year Climate Normal data for the Ann Arbor area. They represent historical averages, not predictions. In any given year, the actual last frost could be 2-3 weeks earlier or later. Microclimates within Ann Arbor (urban heat islands, hilltops, low-lying valleys) can also shift your local frost dates by a week or more.
Start warm-season seeds indoors 6-8 weeks before your last frost (April 22) to maximize your 176-day window. Direct sow cold-hardy crops like peas and lettuce 3-4 weeks before last frost. Every week of early indoor starting matters at this season length. Enter your zip code for exact dates.