U.S. Frost Dates by Weather Station

NOAA station USC00434120 · Vermont

Frost Dates for Island Pond, VT

NOAA weather station Island Pond (USC00434120), Vermont · elevation 1200 ft (366 m) · hardiness zone 4a*

  • Lower-risk planting dateafter June 3only 1 spring in 10 still has a frost later
  • Typical last frostMay 1950% chance of a frost after it
  • Typical first fall frostSeptember 2950% chance of a frost before it
  • Frost-free season129 daystypical year, 32°F
  • Hardiness zone4acalculated*

The year at a glance

Frost season at Island Pond, VTSpring: a frost after May 3 in 9 years out of 10, after May 19 in half of the years, after June 3 in 1 year out of 10. Fall: the first frost comes before September 14 in 1 year out of 10, before September 29 in half of the years, before October 13 in 9 years out of 10. Typical frost-free season: 129 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 19First frost ~Sep 29Frost season at Island Pond, VTSpring: a frost after May 3 in 9 years out of 10, after May 19 in half of the years, after June 3 in 1 year out of 10. Fall: the first frost comes before September 14 in 1 year out of 10, before September 29 in half of the years, before October 13 in 9 years out of 10. Typical frost-free season: 129 days.JFMAMJJASONDLast frost ~May 19First frost ~Sep 29
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)June 3September 14
50% (typical)May 19September 29
90% (likely)May 3October 13
Frost-free season (32°F, 50% chance)
129 days
Hard frost (28°F), last in spring, 50% chance after
May 5
Hard frost (28°F), first in fall, 50% chance before
October 9

The last 15 years (2006–2020 normals)

Typical last frost May 21 (2 days later than the 30-year normal), typical first fall frost September 29. Frost-free season 131 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 Island Pond: chance of a frost after this dateSpring, chance of a frost after the date: 10% June 3, 20% May 30, 30% May 26, 40% May 22, 50% May 19, 60% May 17, 70% May 13, 80% May 9, 90% May 3. Observed last spring frost in recent years: 2021 May 30, 2022 May 24, 2023 May 26, 2024 April 27, 2025 May 12, 2026 May 23.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1Jun 3May 19May 32021: May 302022: May 242023: May 262024: April 272025: May 122026: May 23Fall at Island Pond: chance of a frost before this dateFall, chance of a frost before the date: 10% September 14, 20% September 19, 30% September 23, 40% September 26, 50% September 29, 60% October 1, 70% October 4, 80% October 7, 90% October 13. Observed first fall frost in recent years: 2021 October 25, 2022 September 30, 2023 October 13, 2024 October 8, 2025 September 20.Fall: first frostChance of a frost before this date10%50%90%Sep 1Oct 1Nov 1Sep 14Sep 29Oct 132021: October 252022: September 302023: October 132024: October 82025: September 20
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 30October 25
2022May 24September 30
2023May 26October 13
2024April 27October 8
2025May 12September 20
2026May 23season not over yet

What these dates mean

September 14 marks the cautious fall date for finishing the harvest of tender crops in Island Pond, since only a 10% chance of a light frost exists before that day.

For spring, the cautious date for setting out tender crops is June 3, which carries a 10% chance of a light frost later. The 50% date for light frost in spring is May 19, meaning there is a 50% chance of a frost later than this date, while May 3 entails a 90% chance and is a gamble. In fall, the cautious date for ending harvest is September 14, with a 10% chance of a frost earlier. The 50% date for light frost in fall is September 29, meaning there is a 50% chance of a frost earlier than this date, and October 13 carries a 90% chance, making it risky.

A hard frost at 28 °F, indicated by the 50% dates May 5 and October 9, 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 June 3" 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 14" 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 Island Pond, VTNumbered nearest stations: 1 — Newport, VT — 17 mi; 2 — Colebrook, NH — 18 mi; 3 — Lancaster, NH — 27 mi; 4 — Saint Johnsbury, VT — 28 mi; 5 — York Pond, NH — 35 mi.VTME25 mi · 40 km1. Newport, VT — 17 mi12. Colebrook, NH — 18 mi23. Lancaster, NH — 27 mi34. Saint Johnsbury, VT — 28 mi45. York Pond, NH — 35 mi5
  1. Newport, VT 17 mi (28 km)
  2. Colebrook, NH 18 mi (28 km)
  3. Lancaster, NH 27 mi (43 km)
  4. Saint Johnsbury, VT 28 mi (45 km)
  5. York Pond, NH 35 mi (56 km)

Sources

* Hardiness zone 4a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 44.8128, -71.8903.