NOAA station USC00205073 · Michigan
Frost Dates for Manistique, MI
NOAA weather station Manistique WWTP (USC00205073), Michigan · elevation 600 ft (183 m) · hardiness zone 5b*
- Lower-risk planting dateafter May 23only 1 spring in 10 still has a frost later
- Typical last frostMay 950% chance of a frost after it
- Typical first fall frostOctober 1050% chance of a frost before it
- Frost-free season154 daystypical year, 32°F
- Hardiness zone5bcalculated*
The year at a glance
Frost dates (32°F)
| Chance | Last frost in spring after | First frost in fall before |
|---|---|---|
| 10% (unlikely) | May 23 | September 27 |
| 50% (typical) | May 9 | October 10 |
| 90% (likely) | April 27 | October 27 |
- Frost-free season (32°F, 50% chance)
- 154 days
- Hard frost (28°F), last in spring, 50% chance after
- April 27
- Hard frost (28°F), first in fall, 50% chance before
- October 26
The last 15 years (2006–2020 normals)
Typical last frost May 9 (same as the 30-year normal), typical first fall frost October 14 (4 days later). Frost-free season 155 days.
A shorter, more recent NOAA period. The 30-year normals above remain the main reference: 15 years carry more year-to-year noise.
Add these dates to your calendar Yearly reminders for the typical last frost, the lower-risk planting date and the typical first fall frost (.ics).
How the chance of frost changes with the date
What actually happened in recent years
| Year | Last spring frost | First fall frost |
|---|---|---|
| 2021 | May 12 | October 24 |
| 2022 | May 4 | October 8 |
| 2023 | May 17 | October 23 |
| 2024 | April 26 | October 10 |
| 2025 | May 9 | October 25 |
| 2026 | May 21 | season not over yet |
What these dates mean
The 154 days between the 50% dates in Manistique, May 9 and October 10, hold the span when average temperatures typically stay above the light-frost threshold.
The 50% date of May 9 carries a 50 % chance of a frost later, while the 50% date of October 10 carries a 50 % chance of a frost earlier. Gardeners who prefer a cautious approach would wait until the May 23 date, which carries only a 10 % chance of a later frost, to set out tender crops, and would aim to finish harvesting tender crops by the September 27 date, which carries only a 10 % chance of an earlier frost.
The 50% hard-frost dates are April 27 and October 26, marking the midpoint of risk for temperatures dropping to 28 °F, and a hard frost at 28 °F can damage plants more severely than a light frost at 32 °F.
How to read the probabilities
The dates are probabilities from 30 years of weather, not a forecast for this year.
- Spring: "10% after May 23" means that in about one spring out of ten a frost still happens after that date. The 90% date is the earliest: a frost after it happens in most years.
- Fall: "10% before September 27" means that in about one fall out of ten the first frost arrives before that date.
- 50% is the typical date: half of the years are earlier, half are later.
- A light frost (32°F) damages tender plants; a hard frost (28°F) also stops most hardy vegetables.
Nearby weather stations
- Munising, MI 37 mi (60 km)
- St. James 4 SSW Beaver, MI 38 mi (62 km)
- Chatham Experiment Farm 2, MI 42 mi (68 km)
- Washington Island, WI 51 mi (83 km)
- Cross Village, MI 63 mi (102 km)
Sources
- NOAA NCEI U.S. Climate Normals 1991–2020, station USC00205073
- NOAA NCEI U.S. Climate Normals
- PRISM Group, Oregon State University — 2023 USDA Plant Hardiness Zone GIS datasets
- NOAA NCEI U.S. Climate Normals 2006–2020 (15-year normals), station USC00205073
- NOAA NCEI Global Historical Climatology Network – Daily (GHCN-Daily), observed daily minimum temperature, retrieved 2026-10-08
* Hardiness zone 5b: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.
Station coordinates: 45.9511, -86.2514.