U.S. Frost Dates by Weather Station

NOAA station USC00301966 · New York

Frost Dates for Dannemora, NY

NOAA weather station Dannemora (USC00301966), New York · elevation 1340 ft (408 m) · hardiness zone 5a*

  • Lower-risk planting dateafter May 21only 1 spring in 10 still has a frost later
  • Typical last frostMay 650% chance of a frost after it
  • Typical first fall frostOctober 1150% chance of a frost before it
  • Frost-free season157 daystypical year, 32°F
  • Hardiness zone5acalculated*

The year at a glance

Frost season at Dannemora, NYSpring: a frost after April 23 in 9 years out of 10, after May 6 in half of the years, after May 21 in 1 year out of 10. Fall: the first frost comes before September 29 in 1 year out of 10, before October 11 in half of the years, before October 26 in 9 years out of 10. Typical frost-free season: 157 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 6First frost ~Oct 11Frost season at Dannemora, NYSpring: a frost after April 23 in 9 years out of 10, after May 6 in half of the years, after May 21 in 1 year out of 10. Fall: the first frost comes before September 29 in 1 year out of 10, before October 11 in half of the years, before October 26 in 9 years out of 10. Typical frost-free season: 157 days.JFMAMJJASONDLast frost ~May 6First 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 30 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 21September 29
50% (typical)May 6October 11
90% (likely)April 23October 26
Frost-free season (32°F, 50% chance)
157 days
Hard frost (28°F), last in spring, 50% chance after
April 26
Hard frost (28°F), first in fall, 50% chance before
October 22

The last 15 years (2006–2020 normals)

Typical last frost May 4 (2 days earlier than the 30-year normal), typical first fall frost October 15 (4 days later). Frost-free season 161 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 Dannemora: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 21, 20% May 16, 30% May 12, 40% May 9, 50% May 6, 60% May 4, 70% May 1, 80% April 28, 90% April 23. Observed last spring frost in recent years: 2021 May 2, 2022 April 29, 2023 May 18, 2024 April 26.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 21May 6Apr 232021: May 22022: April 292023: May 182024: April 26Fall at Dannemora: chance of a frost before this dateFall, chance of a frost before the date: 10% September 29, 20% October 2, 30% October 5, 40% October 8, 50% October 11, 60% October 13, 70% October 16, 80% October 20, 90% October 26. Observed first fall frost in recent years: 2021 October 23, 2022 October 11, 2023 October 30, 2024 October 17, 2025 October 10.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 29Oct 11Oct 262021: October 232022: October 112023: October 302024: October 172025: 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 2October 23
2022April 29October 11
2023May 18October 30
2024April 26October 17
2025incomplete recordOctober 10
2026incomplete recordseason not over yet

What these dates mean

The 157 days between the 50% dates in Dannemora define the period from May 6 to October 11, marking the span in which a gardener faces an even chance of a light frost later in spring or earlier in fall. The 50% date of May 6 indicates a 50 % chance of a frost later than this date, while the 50% date of October 11 indicates a 50 % chance of a frost earlier than this date.

The cautious spring date for setting out tender crops is the late date of May 21, which carries only a 10 % chance of a later frost; the cautious fall date to finish harvesting tender crops is the early date of September 29, with only a 10 % chance that frost has arrived earlier. A hard frost, recorded at 28 °F, is more damaging than a light frost because the colder temperature can injure plant tissue that survives a 32 °F event. This record reflects 30 years of NOAA observations.

How to read the probabilities

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

  • Spring: "10% after May 21" 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 29" 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 Dannemora, NYNumbered nearest stations: 1 — Peru, NY — 13 mi; 2 — South Hero, VT — 21 mi; 3 — Malone, NY — 30 mi; 4 — Lake Placid, NY — 31 mi; 5 — Burlington, VT — 33 mi.NYVT25 mi · 40 km1. Peru, NY — 13 mi12. South Hero, VT — 21 mi23. Malone, NY — 30 mi34. Lake Placid, NY — 31 mi45. Burlington, VT — 33 mi5
  1. Peru, NY 13 mi (21 km)
  2. South Hero, VT 21 mi (35 km)
  3. Malone, NY 30 mi (48 km)
  4. Lake Placid, NY 31 mi (51 km)
  5. Burlington, VT 33 mi (53 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: 44.7192, -73.7206.