Michigan last frost dates, station by station

One state, 51 days of last frost

The darker band is where eight stations in ten sit — Apr 28 to May 25, a spread of 27 days on its own. The pale ends are real places too: South Haven, at 590 feet, clears frost around Apr 17, and Vanderbilt at 905 feet is still at risk until Jun 7. Those two sit about 191 miles apart north to south, and that is what the gap is: latitude rather than elevation.

This is why one date for a state is not an answer. Plant to the state median in the wrong half of Michigan and you are either throwing away 21 days of season or losing the plants.

Find your nearest station

Every Michigan station in NOAA’s 1991–2020 normals, earliest last frost first. Cautious is the date frost is done by in nine years out of ten. Even odds is the coin flip most seed packets mean. Early is a date frost usually still follows, for gardeners who own row cover and don’t mind using it. Season is that station’s growing season in days, which almost nobody publishes per station.

211 stations listed. Every date is for 32 °F. A station is not your garden. If the nearest one is on the other side of a ridge or a lake from you, it is describing different air — see how far wrong a nearest-station answer can be.

What to do with the spread

Pick the end that matches what you are willing to lose. The cautious date costs you a couple of weeks of season and buys near-certainty. The early date gets the season back and will have you covering plants some years. Most people want the middle and should know it is a coin flip, not a promise.

Our frost lookup does this for your own address rather than your state. It doesn’t read this table. It reads an 820-foot grid built from 26 years of NASA Daymet daily lows, corrected for each square’s own elevation and checked against NOAA’s stations. Different data, same question, answered for your patch of ground rather than the nearest airport.

And once your garden’s in GardenTrack, you get a heads-up when frost’s in your local forecast, so the date stops being something you have to remember.

How we know

Every figure here comes from NOAA NCEI’s U.S. Climate Normals, 1991–2020, the official 30-year record. We keep only stations that freeze in at least nine years out of ten (244 left out nationally), because a station that rarely freezes has no meaningful “last frost” to report and would drag the early end of every warm state to nonsense.

The whole extract is published as a free CSV under CC BY 4.0, so nothing here has to be taken on trust. The method, including the attempts that failed, is written up at how we research frost dates.

A normal is not a forecast. These are thirty-year averages. They tell you what to plan around; they do not tell you what next April will do.