U.S. Frost Dates by Weather Station

NOAA station USW00014838 · Michigan

Frost Dates for Marquette (USW00014838), MI

NOAA weather station Marquette (USW00014838), Michigan · elevation 665 ft (203 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 23only 1 spring in 10 still has a frost later
  • Typical last frostMay 850% chance of a frost after it
  • Typical first fall frostOctober 2150% chance of a frost before it
  • Frost-free season164 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Marquette (USW00014838), MISpring: a frost after April 26 in 9 years out of 10, after May 8 in half of the years, after May 23 in 1 year out of 10. Fall: the first frost comes before October 6 in 1 year out of 10, before October 21 in half of the years, before November 5 in 9 years out of 10. Typical frost-free season: 164 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 8First frost ~Oct 21Frost season at Marquette (USW00014838), MISpring: a frost after April 26 in 9 years out of 10, after May 8 in half of the years, after May 23 in 1 year out of 10. Fall: the first frost comes before October 6 in 1 year out of 10, before October 21 in half of the years, before November 5 in 9 years out of 10. Typical frost-free season: 164 days.JFMAMJJASONDLast frost ~May 8First frost ~Oct 21
frost likely chance fading 90% → 10% frost-free in a typical yearThe year at a glance. Blue: frost is likely; the gradient fades as the chance drops from 90% to 10%; green: the frost-free part of a typical year.

Frost dates (32°F)

Probability of frost, based on 27 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 23October 6
50% (typical)May 8October 21
90% (likely)April 26November 5
Frost-free season (32°F, 50% chance)
164 days
Hard frost (28°F), last in spring, 50% chance after
April 27
Hard frost (28°F), first in fall, 50% chance before
November 2

The last 15 years (2006–2020 normals)

Typical last frost May 8 (same as the 30-year normal), typical first fall frost October 28 (7 days later). Frost-free season 169 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

Spring at Marquette (USW00014838): chance of a frost after this dateSpring, chance of a frost after the date: 10% May 23, 20% May 18, 30% May 15, 40% May 11, 50% May 8, 60% May 5, 70% May 2, 80% April 30, 90% April 26. Observed last spring frost in recent years: 2021 April 27, 2022 May 5, 2023 May 3, 2024 April 29, 2025 May 1, 2026 May 8.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 23May 8Apr 262021: April 272022: May 52023: May 32024: April 292025: May 12026: May 8Fall at Marquette (USW00014838): chance of a frost before this dateFall, chance of a frost before the date: 10% October 6, 20% October 11, 30% October 15, 40% October 18, 50% October 21, 60% October 25, 70% October 28, 80% November 1, 90% November 5. Observed first fall frost in recent years: 2021 November 2, 2022 November 12, 2023 October 29, 2024 November 24, 2025 October 19.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Dec 1Oct 6Oct 21Nov 52021: November 22022: November 122023: October 292024: November 242025: October 19
Two charts, because spring and fall answer different questions: in spring, the chance that a frost still comes after a date; in fall, the chance that the first frost has already come before it. NOAA publishes these odds from 10% to 90%, so the lines stop there. ◆ marks the actual date in each recent year.

What actually happened in recent years

Observed dates of the last spring and first fall frost (32°F) at this station; ◆ marks them on the charts above
YearLast spring frostFirst fall frost
2021April 27November 2
2022May 5November 12
2023May 3October 29
2024April 29November 24
2025May 1October 19
2026May 8season not over yet

What these dates mean

May 23 is the cautious spring date for tender crops in Marquette, offering a 10 % chance that a light frost will occur later, so a gardener can plan to set out those crops with relatively low risk.

The 50 % dates represent the point at which a light frost (32 °F) or a hard frost (28 °F) is equally likely to happen. The 32 °F median date is May 8, and the hard-frost median date is April 27; neither is a frost date, but they tell a gardener that odds are even for a frost after those days. In fall, the cautious date is October 6, carrying a 10 % chance that a light frost has already arrived, allowing the gardener to finish harvesting tender crops.

A hard frost at 28 °F can injure plants that survive a light frost at 32 °F, making it a more critical threshold.

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 October 6" 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

Map of weather stations near Marquette (USW00014838), MINumbered nearest stations: 1 — Marquette (USW00094850), MI — 8 mi; 2 — Chatham Experiment Farm 2, MI — 26 mi; 3 — Munising, MI — 35 mi; 4 — near Kingsford, MI — 62 mi; 5 — Hancock, MI — 67 mi.MIWI25 mi · 40 km1. Marquette (USW00094850), MI — 8 mi12. Chatham Experiment Farm 2, MI — 26 mi23. Munising, MI — 35 mi34. near Kingsford, MI — 62 mi45. Hancock, MI — 67 mi5
  1. Marquette (USW00094850), MI 8 mi (13 km)
  2. Chatham Experiment Farm 2, MI 26 mi (42 km)
  3. Munising, MI 35 mi (57 km)
  4. near Kingsford, MI 62 mi (100 km)
  5. Hancock, MI 67 mi (108 km)

Sources

* Hardiness zone 6a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 46.5458, -87.3794.