U.S. Frost Dates by Weather Station

NOAA station USC00200925 · Michigan

Frost Dates near Boyne City, MI

NOAA weather station Boyne Falls (USC00200925), Michigan · elevation 728 ft (222 m) · hardiness zone 5a*

Boyne City is the nearest town to the station (6.0 mi away) in GeoNames (CC BY 4.0). The dates below are measured at the station, not in the town itself.

  • Lower-risk planting dateafter June 6only 1 spring in 10 still has a frost later
  • Typical last frostMay 2350% chance of a frost after it
  • Typical first fall frostOctober 350% chance of a frost before it
  • Frost-free season133 daystypical year, 32°F
  • Hardiness zone5acalculated*

The year at a glance

Frost season near Boyne City, MISpring: a frost after May 4 in 9 years out of 10, after May 23 in half of the years, after June 6 in 1 year out of 10. Fall: the first frost comes before September 16 in 1 year out of 10, before October 3 in half of the years, before October 19 in 9 years out of 10. Typical frost-free season: 133 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 23First frost ~Oct 3Frost season near Boyne City, MISpring: a frost after May 4 in 9 years out of 10, after May 23 in half of the years, after June 6 in 1 year out of 10. Fall: the first frost comes before September 16 in 1 year out of 10, before October 3 in half of the years, before October 19 in 9 years out of 10. Typical frost-free season: 133 days.JFMAMJJASONDLast frost ~May 23First frost ~Oct 3
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.Today

Frost dates (32°F)

Probability of frost, based on 29 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)June 6September 16
50% (typical)May 23October 3
90% (likely)May 4October 19
Frost-free season (32°F, 50% chance)
133 days
Hard frost (28°F), last in spring, 50% chance after
May 10
Hard frost (28°F), first in fall, 50% chance before
October 16

The last 15 years (2006–2020 normals)

Typical last frost May 20 (3 days earlier than the 30-year normal), typical first fall frost October 7 (4 days later). Frost-free season 137 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 near Boyne City: chance of a frost after this dateSpring, chance of a frost after the date: 10% June 6, 20% June 1, 30% May 29, 40% May 26, 50% May 23, 60% May 20, 70% May 17, 80% May 12, 90% May 4. Observed last spring frost in recent years: 2021 May 30, 2022 May 23, 2023 May 26, 2024 April 25, 2025 June 1, 2026 May 21.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1Jun 6May 23May 42021: May 302022: May 232023: May 262024: April 252025: June 12026: May 21Fall near Boyne City: chance of a frost before this dateFall, chance of a frost before the date: 10% September 16, 20% September 22, 30% September 27, 40% September 30, 50% October 3, 60% October 5, 70% October 9, 80% October 12, 90% October 19. Observed first fall frost in recent years: 2021 October 18, 2022 September 23, 2023 October 12, 2024 October 10, 2025 October 9.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 16Oct 3Oct 192021: October 182022: September 232023: October 122024: October 102025: October 9
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
2021May 30October 18
2022May 23September 23
2023May 26October 12
2024April 25October 10
2025June 1October 9
2026May 21season not over yet

What these dates mean

Setting out tender crops on the early spring date, May 4, is a gamble with a 90% chance of a frost later than that day. The cautious spring date for planting tender crops is June 6, which carries only a 10% chance of a frost later.

For a gardener, the 50% date is May 23, meaning a 50% chance of a frost later than this date, and the fall 50% date is October 3, meaning a 50% chance of a frost earlier than this date. Finishing tender crops in fall is guided by the cautious date of September 16, which holds just a 10% chance of a frost earlier.

Hard frost at 28 °F is more damaging than a light frost at 32 °F; the median hard-frost dates are May 10 in spring and October 16 in fall, and the interval between the two 32 °F 50% dates is 133 days, based on 29 years of record.

How to read the probabilities

The dates are probabilities from 30 years of weather, not a forecast for this year.

  • Spring: "10% after June 6" 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 16" 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 Boyne City, MINumbered nearest stations: 1 — Gaylord, MI — 14 mi; 2 — Petoskey, MI — 15 mi; 3 — Vanderbilt, MI — 23 mi; 4 — Pellston, MI — 28 mi; 5 — Kalkaska, MI — 33 mi.MI25 mi · 40 km1. Gaylord, MI — 14 mi12. Petoskey, MI — 15 mi23. Vanderbilt, MI — 23 mi34. Pellston, MI — 28 mi45. Kalkaska, MI — 33 mi5
  1. Gaylord, MI 14 mi (22 km)
  2. Petoskey, MI 15 mi (23 km)
  3. Vanderbilt, MI 23 mi (37 km)
  4. Pellston, MI 28 mi (45 km)
  5. Kalkaska, MI 33 mi (53 km)

Sources

* Hardiness zone 5a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 45.1672, -84.9139.