U.S. Frost Dates by Weather Station

NOAA station USC00202250 · Michigan

Frost Dates for Dowagiac, MI

NOAA weather station Dowagiac 1 W (USC00202250), Michigan · elevation 740 ft (226 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 22only 1 spring in 10 still has a frost later
  • Typical last frostMay 450% chance of a frost after it
  • Typical first fall frostOctober 1150% chance of a frost before it
  • Frost-free season158 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Dowagiac, MISpring: a frost after April 21 in 9 years out of 10, after May 4 in half of the years, after May 22 in 1 year out of 10. Fall: the first frost comes before September 27 in 1 year out of 10, before October 11 in half of the years, before October 27 in 9 years out of 10. Typical frost-free season: 158 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 4First frost ~Oct 11Frost season at Dowagiac, MISpring: a frost after April 21 in 9 years out of 10, after May 4 in half of the years, after May 22 in 1 year out of 10. Fall: the first frost comes before September 27 in 1 year out of 10, before October 11 in half of the years, before October 27 in 9 years out of 10. Typical frost-free season: 158 days.JFMAMJJASONDLast frost ~May 4First frost ~Oct 11
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 25 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 22September 27
50% (typical)May 4October 11
90% (likely)April 21October 27
Frost-free season (32°F, 50% chance)
158 days
Hard frost (28°F), last in spring, 50% chance after
April 24
Hard frost (28°F), first in fall, 50% chance before
October 26

The last 15 years (2006–2020 normals)

Typical last frost May 2 (2 days earlier than the 30-year normal), typical first fall frost October 18 (7 days later). Frost-free season 165 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 Dowagiac: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 22, 20% May 16, 30% May 11, 40% May 8, 50% May 4, 60% May 2, 70% April 29, 80% April 25, 90% April 21. Observed last spring frost in recent years: 2021 May 14, 2022 April 27, 2023 May 2, 2024 April 27, 2025 May 10.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 22May 4Apr 212021: May 142022: April 272023: May 22024: April 272025: May 10Fall at Dowagiac: chance of a frost before this dateFall, chance of a frost before the date: 10% September 27, 20% October 1, 30% October 5, 40% October 8, 50% October 11, 60% October 14, 70% October 17, 80% October 22, 90% October 27. Observed first fall frost in recent years: 2021 October 24, 2022 October 20, 2023 October 23, 2024 October 17, 2025 October 25.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 27Oct 11Oct 272021: October 242022: October 202023: October 232024: October 172025: 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 14October 24
2022April 27October 20
2023May 2October 23
2024April 27October 17
2025May 10October 25
2026incomplete recordseason not over yet

What these dates mean

Setting out tender crops on the early spring date, April 21, carries a 90 % chance of a frost later that season, so it is a gamble for Dowagiac gardeners. The 50 % light-frost dates – May 4 in spring and October 11 in fall – indicate when a frost has an even chance of occurring. The 50 % hard-frost dates are April 24 and October 26, serving as the median moments for a 28 °F frost.

For a cautious plan, the spring light-frost date to aim for is May 22, when only a 10 % chance of frost later remains, and the fall cautious date is September 27, with a 10 % chance of frost earlier. A hard frost at 28 °F can damage plants that would otherwise survive a light frost at 32 °F, so it represents a greater risk.

How to read the probabilities

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

  • Spring: "10% after May 22" 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

Map of weather stations near Dowagiac, MINumbered nearest stations: 1 — Benton Harbor, MI — 18 mi; 2 — near South Bend, IN — 21 mi; 3 — Three Rivers, MI — 26 mi; 4 — Goshen, IN — 32 mi; 5 — Lakeville, IN — 32 mi.MIOHIL25 mi · 40 km1. Benton Harbor, MI — 18 mi12. near South Bend, IN — 21 mi23. Three Rivers, MI — 26 mi34. Goshen, IN — 32 mi45. Lakeville, IN — 32 mi5
  1. Benton Harbor, MI 18 mi (29 km)
  2. near South Bend, IN 21 mi (35 km)
  3. Three Rivers, MI 26 mi (41 km)
  4. Goshen, IN 32 mi (52 km)
  5. Lakeville, IN 32 mi (52 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: 41.9856, -86.1319.