U.S. Frost Dates by Weather Station

NOAA station USC00174927 · Maine

Frost Dates for Madison, ME

NOAA weather station Madison (USC00174927), Maine · elevation 220 ft (67 m) · hardiness zone 5a*

  • Lower-risk planting dateafter May 20only 1 spring in 10 still has a frost later
  • Typical last frostMay 850% chance of a frost after it
  • Typical first fall frostOctober 550% chance of a frost before it
  • Frost-free season149 daystypical year, 32°F
  • Hardiness zone5acalculated*

The year at a glance

Frost season at Madison, MESpring: a frost after April 28 in 9 years out of 10, after May 8 in half of the years, after May 20 in 1 year out of 10. Fall: the first frost comes before September 24 in 1 year out of 10, before October 5 in half of the years, before October 20 in 9 years out of 10. Typical frost-free season: 149 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 8First frost ~Oct 5Frost season at Madison, MESpring: a frost after April 28 in 9 years out of 10, after May 8 in half of the years, after May 20 in 1 year out of 10. Fall: the first frost comes before September 24 in 1 year out of 10, before October 5 in half of the years, before October 20 in 9 years out of 10. Typical frost-free season: 149 days.JFMAMJJASONDLast frost ~May 8First frost ~Oct 5
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)May 20September 24
50% (typical)May 8October 5
90% (likely)April 28October 20
Frost-free season (32°F, 50% chance)
149 days
Hard frost (28°F), last in spring, 50% chance after
April 28
Hard frost (28°F), first in fall, 50% chance before
October 18

The last 15 years (2006–2020 normals)

Typical last frost May 7 (1 day earlier than the 30-year normal), typical first fall frost October 7 (2 days later). Frost-free season 152 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 Madison: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 20, 20% May 16, 30% May 13, 40% May 11, 50% May 8, 60% May 6, 70% May 4, 80% May 1, 90% April 28. Observed last spring frost in recent years: 2021 May 7, 2022 May 10, 2023 May 19, 2024 April 29, 2025 May 1, 2026 May 22.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 20May 8Apr 282021: May 72022: May 102023: May 192024: April 292025: May 12026: May 22Fall at Madison: chance of a frost before this dateFall, chance of a frost before the date: 10% September 24, 20% September 28, 30% October 1, 40% October 3, 50% October 5, 60% October 7, 70% October 11, 80% October 14, 90% October 20. Observed first fall frost in recent years: 2021 October 24, 2022 October 3, 2023 October 24, 2024 October 15, 2025 October 10.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 24Oct 5Oct 202021: October 242022: October 32023: October 242024: October 152025: October 10
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
2022May 10October 3
2023May 19October 24
2024April 29October 15
2025May 1October 10
2026May 22season not over yet

What these dates mean

Setting out tender crops on April 28 in Madison carries a 90% chance of a frost later that season, making it a gamble for growers who need frost-free conditions.

May 8 is the 50% date for light frost in spring, meaning there is a 50% chance of a frost later than this date; the cautious spring date is May 20, when only a 10% chance remains. In fall, October 5 is the 50% date, with a 50% chance of a frost earlier than this date, and the cautious fall date is September 24, when the chance of an earlier frost is just 10%.

A hard frost at 28°F can damage plant tissue more severely than a light frost at 32°F, so the 28°F thresholds—April 28 in spring and October 18 in fall—signal the more critical 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 20" 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 24" 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 Madison, MENumbered nearest stations: 1 — Farmington, ME — 15 mi; 2 — near Waterville, ME — 22 mi; 3 — Corinna, ME — 33 mi; 4 — near Augusta, ME — 33 mi; 5 — Rangeley, ME — 39 mi.MENH25 mi · 40 km1. Farmington, ME — 15 mi12. near Waterville, ME — 22 mi23. Corinna, ME — 33 mi34. near Augusta, ME — 33 mi45. Rangeley, ME — 39 mi5
  1. Farmington, ME 15 mi (24 km)
  2. near Waterville, ME 22 mi (35 km)
  3. Corinna, ME 33 mi (53 km)
  4. near Augusta, ME 33 mi (54 km)
  5. Rangeley, ME 39 mi (62 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: 44.7975, -69.8889.