U.S. Frost Dates by Weather Station

NOAA station USW00014605 · Maine

Frost Dates near Augusta, ME

NOAA weather station Augusta State Airport (USW00014605), Maine · elevation 350 ft (107 m) · hardiness zone 5b*

Augusta is the nearest town to the station (1.1 mi away) in GeoNames (CC BY 4.0). The dates below are measured at the station, not in the town itself.

  • Lower-risk planting dateafter May 7only 1 spring in 10 still has a frost later
  • Typical last frostApril 2750% chance of a frost after it
  • Typical first fall frostOctober 1650% chance of a frost before it
  • Frost-free season172 daystypical year, 32°F
  • Hardiness zone5bcalculated*

The year at a glance

Frost season near Augusta, MESpring: a frost after April 15 in 9 years out of 10, after April 27 in half of the years, after May 7 in 1 year out of 10. Fall: the first frost comes before October 2 in 1 year out of 10, before October 16 in half of the years, before October 31 in 9 years out of 10. Typical frost-free season: 172 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 27First frost ~Oct 16Frost season near Augusta, MESpring: a frost after April 15 in 9 years out of 10, after April 27 in half of the years, after May 7 in 1 year out of 10. Fall: the first frost comes before October 2 in 1 year out of 10, before October 16 in half of the years, before October 31 in 9 years out of 10. Typical frost-free season: 172 days.JFMAMJJASONDLast frost ~Apr 27First frost ~Oct 16
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 27 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 7October 2
50% (typical)April 27October 16
90% (likely)April 15October 31
Frost-free season (32°F, 50% chance)
172 days
Hard frost (28°F), last in spring, 50% chance after
April 15
Hard frost (28°F), first in fall, 50% chance before
October 31

The last 15 years (2006–2020 normals)

Typical last frost April 23 (4 days earlier than the 30-year normal), typical first fall frost October 21 (5 days later). Frost-free season 181 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 near Augusta: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 7, 20% May 3, 30% May 1, 40% April 29, 50% April 27, 60% April 25, 70% April 22, 80% April 19, 90% April 15. Observed last spring frost in recent years: 2021 April 22, 2022 April 21, 2023 April 10, 2024 April 27, 2025 April 10, 2026 April 25.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 7Apr 27Apr 152021: April 222022: April 212023: April 102024: April 272025: April 102026: April 25Fall near Augusta: chance of a frost before this dateFall, chance of a frost before the date: 10% October 2, 20% October 6, 30% October 10, 40% October 13, 50% October 16, 60% October 19, 70% October 22, 80% October 26, 90% October 31. Observed first fall frost in recent years: 2021 November 3, 2022 October 11, 2023 October 31, 2024 October 17, 2025 November 2.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 2Oct 16Oct 312021: November 32022: October 112023: October 312024: October 172025: November 2
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 22November 3
2022April 21October 11
2023April 10October 31
2024April 27October 17
2025April 10November 2
2026April 25season not over yet

What these dates mean

May 7 is the cautious spring date for the Augusta area; on this day there is only a 10 % chance of a light frost occurring later, so a gardener can plan to set out tender crops with minimal risk.

The median point for light-frost risk is April 27 in spring, when the chance of a frost later than this date is 50 %. In fall the 50 % date is October 16, marking an even odds that a frost has arrived earlier. For a conservative schedule the cautious fall date is October 2, which carries only a 10 % chance that a light frost has already occurred, allowing the gardener to finish harvesting tender crops.

A hard frost at 28 °F is more damaging than a light frost at 32 °F because it can injure plant tissue that would survive the milder temperature.

How to read the probabilities

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

  • Spring: "10% after May 7" 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 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 Augusta, MENumbered nearest stations: 1 — Gardiner, ME — 7 mi; 2 — near Waterville, ME — 16 mi; 3 — Newcastle, ME — 23 mi; 4 — Farmington, ME — 31 mi; 5 — Madison, ME — 33 mi.NH25 mi · 40 km1. Gardiner, ME — 7 mi12. near Waterville, ME — 16 mi23. Newcastle, ME — 23 mi34. Farmington, ME — 31 mi45. Madison, ME — 33 mi5
  1. Gardiner, ME 7 mi (11 km)
  2. near Waterville, ME 16 mi (26 km)
  3. Newcastle, ME 23 mi (37 km)
  4. Farmington, ME 31 mi (50 km)
  5. Madison, ME 33 mi (54 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: 44.3206, -69.7972.