U.S. Frost Dates by Weather Station

NOAA station USW00014841 · Michigan

Frost Dates for Pellston, MI

NOAA weather station Pellston Regional Airport (USW00014841), Michigan · elevation 705 ft (215 m) · hardiness zone 4b*

  • Lower-risk planting dateafter June 21only 1 spring in 10 still has a frost later
  • Typical last frostMay 3150% chance of a frost after it
  • Typical first fall frostSeptember 1850% chance of a frost before it
  • Frost-free season108 daystypical year, 32°F
  • Hardiness zone4bcalculated*

The year at a glance

Frost season at Pellston, MISpring: a frost after May 16 in 9 years out of 10, after May 31 in half of the years, after June 21 in 1 year out of 10. Fall: the first frost comes before September 2 in 1 year out of 10, before September 18 in half of the years, before October 3 in 9 years out of 10. Typical frost-free season: 108 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 31First frost ~Sep 18Frost season at Pellston, MISpring: a frost after May 16 in 9 years out of 10, after May 31 in half of the years, after June 21 in 1 year out of 10. Fall: the first frost comes before September 2 in 1 year out of 10, before September 18 in half of the years, before October 3 in 9 years out of 10. Typical frost-free season: 108 days.JFMAMJJASONDLast frost ~May 31First frost ~Sep 18
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 30 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)June 21September 2
50% (typical)May 31September 18
90% (likely)May 16October 3
Frost-free season (32°F, 50% chance)
108 days
Hard frost (28°F), last in spring, 50% chance after
May 19
Hard frost (28°F), first in fall, 50% chance before
October 1

The last 15 years (2006–2020 normals)

Typical last frost May 29 (2 days earlier than the 30-year normal), typical first fall frost September 22 (4 days later). Frost-free season 115 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 Pellston: chance of a frost after this dateSpring, chance of a frost after the date: 10% June 21, 20% June 11, 30% June 6, 40% June 2, 50% May 31, 60% May 29, 70% May 26, 80% May 22, 90% May 16. Observed last spring frost in recent years: 2021 May 30, 2022 June 4, 2023 May 27, 2024 May 16, 2025 June 2, 2026 May 22.Spring: last frostChance of a frost after this date10%50%90%Jun 1Jul 1Jun 21May 31May 162021: May 302022: June 42023: May 272024: May 162025: June 22026: May 22Fall at Pellston: chance of a frost before this dateFall, chance of a frost before the date: 10% September 2, 20% September 9, 30% September 13, 40% September 16, 50% September 18, 60% September 21, 70% September 26, 80% September 29, 90% October 3. Observed first fall frost in recent years: 2021 October 18, 2022 September 23, 2023 October 12, 2024 October 2, 2025 October 8.Fall: first frostChance of a frost before this date10%50%90%Sep 1Oct 1Sep 2Sep 18Oct 32021: October 182022: September 232023: October 122024: October 22025: October 8
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
2022June 4September 23
2023May 27October 12
2024May 16October 2
2025June 2October 8
2026May 22season not over yet

What these dates mean

Setting out tender crops on the early spring date of May 16 in Pellston carries a 90% chance of frost, making it a gamble for growers.

The cautious plan uses the June 21 light-frost date, which has only a 10% chance of frost later, for planting tender crops, and the September 2 light-frost date, with a 10% chance of frost earlier, for finishing their harvest. May 31 marks the point where the probability of a light frost is 50%, and September 18 marks the point where the probability of a light frost is 50%.

Because a hard frost at 28 °F (the median dates are May 19 in spring and October 1 in fall) can injure plant tissue that would survive a 32 °F light frost, it is a more critical threshold for gardeners.

How to read the probabilities

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

  • Spring: "10% after June 21" 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 2" 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 Pellston, MINumbered nearest stations: 1 — Cross Village, MI — 12 mi; 2 — Petoskey, MI — 16 mi; 3 — Cheboygan, MI — 17 mi; 4 — near Boyne City, MI — 28 mi; 5 — Onaway, MI — 30 mi.MI25 mi · 40 km1. Cross Village, MI — 12 mi12. Petoskey, MI — 16 mi23. Cheboygan, MI — 17 mi34. near Boyne City, MI — 28 mi45. Onaway, MI — 30 mi5
  1. Cross Village, MI 12 mi (19 km)
  2. Petoskey, MI 16 mi (26 km)
  3. Cheboygan, MI 17 mi (27 km)
  4. near Boyne City, MI 28 mi (45 km)
  5. Onaway, MI 30 mi (48 km)

Sources

* Hardiness zone 4b: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 45.5644, -84.7928.