U.S. Frost Dates by Weather Station

NOAA station USC00173046 · Maine

Frost Dates for Gardiner, ME

NOAA weather station Gardiner (USC00173046), Maine · elevation 133 ft (41 m) · hardiness zone 5b*

  • Lower-risk planting dateafter May 14only 1 spring in 10 still has a frost later
  • Typical last frostMay 150% chance of a frost after it
  • Typical first fall frostOctober 1150% chance of a frost before it
  • Frost-free season163 daystypical year, 32°F
  • Hardiness zone5bcalculated*

The year at a glance

Frost season at Gardiner, MESpring: a frost after April 20 in 9 years out of 10, after May 1 in half of the years, after May 14 in 1 year out of 10. Fall: the first frost comes before September 30 in 1 year out of 10, before October 11 in half of the years, before October 28 in 9 years out of 10. Typical frost-free season: 163 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 1First frost ~Oct 11Frost season at Gardiner, MESpring: a frost after April 20 in 9 years out of 10, after May 1 in half of the years, after May 14 in 1 year out of 10. Fall: the first frost comes before September 30 in 1 year out of 10, before October 11 in half of the years, before October 28 in 9 years out of 10. Typical frost-free season: 163 days.JFMAMJJASONDLast frost ~May 1First 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 14September 30
50% (typical)May 1October 11
90% (likely)April 20October 28
Frost-free season (32°F, 50% chance)
163 days
Hard frost (28°F), last in spring, 50% chance after
April 19
Hard frost (28°F), first in fall, 50% chance before
October 25

The last 15 years (2006–2020 normals)

Typical last frost April 26 (5 days earlier than the 30-year normal), typical first fall frost October 16 (5 days later). Frost-free season 170 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 Gardiner: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 14, 20% May 8, 30% May 5, 40% May 3, 50% May 1, 60% April 29, 70% April 27, 80% April 24, 90% April 20. Observed last spring frost in recent years: 2021 April 23, 2022 May 12, 2024 April 28.Spring: last frostChance of a frost after this date10%50%90%May 1May 14May 1Apr 202021: April 232022: May 122024: April 28Fall at Gardiner: chance of a frost before this dateFall, chance of a frost before the date: 10% September 30, 20% October 2, 30% October 6, 40% October 8, 50% October 11, 60% October 14, 70% October 17, 80% October 22, 90% October 28. Observed first fall frost in recent years: 2021 October 29, 2022 October 4, 2023 November 1, 2024 October 17.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 30Oct 11Oct 282021: October 292022: October 42023: November 12024: October 17
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
2021April 23October 29
2022May 12October 4
2023incomplete recordNovember 1
2024April 28October 17
2025no datano data
2026no dataseason not over yet

What these dates mean

May 14 is the cautious spring date for setting out tender crops in Gardiner, giving a gardener a low-risk point to begin planting. The earlier date, April 20, carries a 90% chance of a light frost and should be treated as a gamble.

The 50% light-frost dates are May 1 and October 11; each carries a 50% chance of a frost later (May 1) or earlier (October 11). For fall, September 30 is the cautious date to finish harvesting tender crops, with only a 10% chance that a light frost has arrived. The median hard-frost dates are April 19 in spring and October 25 in fall, and a hard frost at 28 °F can damage plants more severely than 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 14" 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 30" 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 Gardiner, MENumbered nearest stations: 1 — near Augusta, ME — 7 mi; 2 — Newcastle, ME — 17 mi; 3 — near Waterville, ME — 22 mi; 4 — West Rockport, ME — 32 mi; 5 — Gray, ME — 32 mi.NH25 mi · 40 km1. near Augusta, ME — 7 mi12. Newcastle, ME — 17 mi23. near Waterville, ME — 22 mi34. West Rockport, ME — 32 mi45. Gray, ME — 32 mi5
  1. near Augusta, ME 7 mi (11 km)
  2. Newcastle, ME 17 mi (28 km)
  3. near Waterville, ME 22 mi (36 km)
  4. West Rockport, ME 32 mi (51 km)
  5. Gray, ME 32 mi (52 km)

Sources

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

Station coordinates: 44.2203, -69.7889.