U.S. Frost Dates by Weather Station

NOAA station USW00094860 · Michigan

Frost Dates for Grand Rapids, MI

NOAA weather station Grand Rapids (USW00094860), Michigan · elevation 778 ft (237 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 15only 1 spring in 10 still has a frost later
  • Typical last frostApril 2950% chance of a frost after it
  • Typical first fall frostOctober 2050% chance of a frost before it
  • Frost-free season174 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Grand Rapids, MISpring: a frost after April 14 in 9 years out of 10, after April 29 in half of the years, after May 15 in 1 year out of 10. Fall: the first frost comes before October 4 in 1 year out of 10, before October 20 in half of the years, before November 2 in 9 years out of 10. Typical frost-free season: 174 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 29First frost ~Oct 20Frost season at Grand Rapids, MISpring: a frost after April 14 in 9 years out of 10, after April 29 in half of the years, after May 15 in 1 year out of 10. Fall: the first frost comes before October 4 in 1 year out of 10, before October 20 in half of the years, before November 2 in 9 years out of 10. Typical frost-free season: 174 days.JFMAMJJASONDLast frost ~Apr 29First frost ~Oct 20
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)May 15October 4
50% (typical)April 29October 20
90% (likely)April 14November 2
Frost-free season (32°F, 50% chance)
174 days
Hard frost (28°F), last in spring, 50% chance after
April 16
Hard frost (28°F), first in fall, 50% chance before
November 2

The last 15 years (2006–2020 normals)

Typical last frost April 28 (1 day earlier than the 30-year normal), typical first fall frost October 22 (2 days later). Frost-free season 177 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 Grand Rapids: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 15, 20% May 8, 30% May 4, 40% May 1, 50% April 29, 60% April 25, 70% April 22, 80% April 18, 90% April 14. Observed last spring frost in recent years: 2021 May 7, 2022 April 28, 2023 April 27, 2024 April 25, 2025 April 17, 2026 May 12.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 15Apr 29Apr 142021: May 72022: April 282023: April 272024: April 252025: April 172026: May 12Fall at Grand Rapids: chance of a frost before this dateFall, chance of a frost before the date: 10% October 4, 20% October 9, 30% October 13, 40% October 16, 50% October 20, 60% October 22, 70% October 26, 80% October 29, 90% November 2. Observed first fall frost in recent years: 2021 October 24, 2022 October 8, 2023 October 23, 2024 October 27, 2025 October 25.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 4Oct 20Nov 22021: October 242022: October 82023: October 232024: October 272025: October 25
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 7October 24
2022April 28October 8
2023April 27October 23
2024April 25October 27
2025April 17October 25
2026May 12season not over yet

What these dates mean

May 15 marks the cautious spring date for Grand Rapids, when there is only a 10 % chance of a light frost later, allowing a gardener to set out tender crops with minimal risk.

The median light-frost dates, April 29 in spring and October 20 in fall, represent the point at which a frost is equally likely to occur before or after, giving a clear reference for timing decisions. For a guarded plan, the spring cautious date is May 15 and the fall cautious date is October 4, each carrying a 10 % chance of a light frost earlier (fall) or later (spring). The 50 % hard-frost dates are April 16 and November 2; a hard frost at 28 °F can damage plants that would survive 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 15" 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 4" 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 Grand Rapids, MINumbered nearest stations: 1 — Hastings, MI — 22 mi; 2 — near Norton Shores, MI — 40 mi; 3 — Charlotte, MI — 44 mi; 4 — near Lansing, MI — 50 mi; 5 — Big Rapids, MI — 56 mi.MI25 mi · 40 km1. Hastings, MI — 22 mi12. near Norton Shores, MI — 40 mi23. Charlotte, MI — 44 mi34. near Lansing, MI — 50 mi45. Big Rapids, MI — 56 mi5
  1. Hastings, MI 22 mi (35 km)
  2. near Norton Shores, MI 40 mi (64 km)
  3. Charlotte, MI 44 mi (70 km)
  4. near Lansing, MI 50 mi (80 km)
  5. Big Rapids, MI 56 mi (91 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: 42.8939, -85.5447.