U.S. Frost Dates by Weather Station

NOAA station USC00279966 · New Hampshire

Frost Dates for York Pond, NH

NOAA weather station York Pond (USC00279966), New Hampshire · elevation 1519 ft (463 m) · hardiness zone 4b*

  • Lower-risk planting dateafter June 6only 1 spring in 10 still has a frost later
  • Typical last frostMay 2350% chance of a frost after it
  • Typical first fall frostSeptember 2250% chance of a frost before it
  • Frost-free season122 daystypical year, 32°F
  • Hardiness zone4bcalculated*

The year at a glance

Frost season at York Pond, NHSpring: a frost after May 8 in 9 years out of 10, after May 23 in half of the years, after June 6 in 1 year out of 10. Fall: the first frost comes before September 9 in 1 year out of 10, before September 22 in half of the years, before October 3 in 9 years out of 10. Typical frost-free season: 122 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 23First frost ~Sep 22Frost season at York Pond, NHSpring: a frost after May 8 in 9 years out of 10, after May 23 in half of the years, after June 6 in 1 year out of 10. Fall: the first frost comes before September 9 in 1 year out of 10, before September 22 in half of the years, before October 3 in 9 years out of 10. Typical frost-free season: 122 days.JFMAMJJASONDLast frost ~May 23First frost ~Sep 22
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)June 6September 9
50% (typical)May 23September 22
90% (likely)May 8October 3
Frost-free season (32°F, 50% chance)
122 days
Hard frost (28°F), last in spring, 50% chance after
May 8
Hard frost (28°F), first in fall, 50% chance before
October 2

The last 15 years (2006–2020 normals)

Typical last frost May 22 (1 day earlier than the 30-year normal), typical first fall frost September 24 (2 days later). Frost-free season 123 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 York Pond: chance of a frost after this dateSpring, chance of a frost after the date: 10% June 6, 20% June 2, 30% May 30, 40% May 26, 50% May 23, 60% May 20, 70% May 17, 80% May 13, 90% May 8. Observed last spring frost in recent years: 2021 May 28, 2022 May 27, 2023 May 26, 2024 April 28.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1Jun 6May 23May 82021: May 282022: May 272023: May 262024: April 28Fall at York Pond: chance of a frost before this dateFall, chance of a frost before the date: 10% September 9, 20% September 13, 30% September 16, 40% September 19, 50% September 22, 60% September 25, 70% September 27, 80% September 30, 90% October 3. Observed first fall frost in recent years: 2021 September 29, 2022 September 30, 2023 October 12, 2024 October 17, 2025 September 20.Fall: first frostChance of a frost before this date10%50%90%Sep 1Oct 1Sep 9Sep 22Oct 32021: September 292022: September 302023: October 122024: October 172025: 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 28September 29
2022May 27September 30
2023May 26October 12
2024April 28October 17
2025incomplete recordSeptember 20
2026incomplete recordseason not over yet

What these dates mean

June 6 is the cautious spring date, with only a 10% chance of a frost later than this date, allowing a gardener to set out tender crops with relatively low risk.

The 50% date is May 23, a 50% chance of a frost later than this date, and the 50% date is September 22, a 50% chance of a frost earlier than this date. In the fall, September 9 is the cautious date, carrying a 10% chance of a frost earlier than this date, which marks the point at which tender crops can be finished harvesting. Hard-frost thresholds matter more because a 28°F event can damage plants that survive a light 32°F frost.

The 50% hard-frost date in spring is May 8 and in fall is October 2, highlighting when a 28°F frost is equally likely to have occurred or not. These probabilities are drawn from 27 years of NOAA normals.

How to read the probabilities

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

  • Spring: "10% after June 6" 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 9" 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 York Pond, NHNumbered nearest stations: 1 — Berlin, NH — 8 mi; 2 — Lancaster, NH — 12 mi; 3 — Pinkham Notch, NH — 18 mi; 4 — Colebrook, NH — 26 mi; 5 — North Conway, NH — 33 mi.MEVTNH25 mi · 40 km1. Berlin, NH — 8 mi12. Lancaster, NH — 12 mi23. Pinkham Notch, NH — 18 mi34. Colebrook, NH — 26 mi45. North Conway, NH — 33 mi5
  1. Berlin, NH 8 mi (13 km)
  2. Lancaster, NH 12 mi (19 km)
  3. Pinkham Notch, NH 18 mi (28 km)
  4. Colebrook, NH 26 mi (43 km)
  5. North Conway, NH 33 mi (53 km)

Sources

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

Station coordinates: 44.5067, -71.3336.