U.S. Frost Dates by Weather Station

NOAA station USC00304174 · New York

Frost Dates near Ithaca, NY

NOAA weather station Ithaca Cornell University (USC00304174), New York · elevation 960 ft (293 m) · hardiness zone 5b*

Ithaca is the nearest town to the station (2.5 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 26only 1 spring in 10 still has a frost later
  • Typical last frostMay 1150% chance of a frost after it
  • Typical first fall frostOctober 350% chance of a frost before it
  • Frost-free season145 daystypical year, 32°F
  • Hardiness zone5bcalculated*

The year at a glance

Frost season near Ithaca, NYSpring: a frost after April 27 in 9 years out of 10, after May 11 in half of the years, after May 26 in 1 year out of 10. Fall: the first frost comes before September 21 in 1 year out of 10, before October 3 in half of the years, before October 21 in 9 years out of 10. Typical frost-free season: 145 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 11First frost ~Oct 3Frost season near Ithaca, NYSpring: a frost after April 27 in 9 years out of 10, after May 11 in half of the years, after May 26 in 1 year out of 10. Fall: the first frost comes before September 21 in 1 year out of 10, before October 3 in half of the years, before October 21 in 9 years out of 10. Typical frost-free season: 145 days.JFMAMJJASONDLast frost ~May 11First frost ~Oct 3
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 26September 21
50% (typical)May 11October 3
90% (likely)April 27October 21
Frost-free season (32°F, 50% chance)
145 days
Hard frost (28°F), last in spring, 50% chance after
April 30
Hard frost (28°F), first in fall, 50% chance before
October 18

The last 15 years (2006–2020 normals)

Typical last frost May 8 (3 days earlier than the 30-year normal), typical first fall frost October 9 (6 days later). Frost-free season 150 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 Ithaca: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 26, 20% May 21, 30% May 18, 40% May 14, 50% May 11, 60% May 8, 70% May 4, 80% April 30, 90% April 27. Observed last spring frost in recent years: 2021 May 13, 2022 May 9, 2023 May 26, 2024 April 27, 2025 April 28, 2026 May 12.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 26May 11Apr 272021: May 132022: May 92023: May 262024: April 272025: April 282026: May 12Fall near Ithaca: chance of a frost before this dateFall, chance of a frost before the date: 10% September 21, 20% September 25, 30% September 28, 40% October 1, 50% October 3, 60% October 6, 70% October 11, 80% October 15, 90% October 21. Observed first fall frost in recent years: 2021 October 28, 2022 October 16, 2023 October 31, 2024 October 11, 2025 October 2.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 21Oct 3Oct 212021: October 282022: October 162023: October 312024: October 112025: October 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
2021May 13October 28
2022May 9October 16
2023May 26October 31
2024April 27October 11
2025April 28October 2
2026May 12season not over yet

What these dates mean

May 26 is the cautious spring date for the Ithaca area, with only a 10% chance of a light frost later than that day. A gardener can schedule the first planting of tender crops on or after this date with low frost risk.

The 50% date is May 11, indicating a 50% chance of a frost later than this date in spring, while the 50% date is October 3, indicating a 50% chance of a frost earlier than this date in fall. The cautious fall date for finishing tender crops is September 21, when there is only a 10% chance a light frost has arrived earlier. The 50% hard-frost dates are April 30 and October 18, each representing even odds for a hard frost.

Hard frost at 28°F can damage plants more severely than a light frost at 32°F, so those dates matter for protecting vulnerable crops.

How to read the probabilities

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

  • Spring: "10% after May 26" 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 21" 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 Ithaca, NYNumbered nearest stations: 1 — near Union Springs, NY — 22 mi; 2 — Binghamton, NY — 29 mi; 3 — Elmira, NY — 31 mi; 4 — Geneva, NY — 42 mi; 5 — Norwich, NY — 48 mi.NYPA25 mi · 40 km1. near Union Springs, NY — 22 mi12. Binghamton, NY — 29 mi23. Elmira, NY — 31 mi34. Geneva, NY — 42 mi45. Norwich, NY — 48 mi5
  1. near Union Springs, NY 22 mi (36 km)
  2. Binghamton, NY 29 mi (47 km)
  3. Elmira, NY 31 mi (50 km)
  4. Geneva, NY 42 mi (67 km)
  5. Norwich, NY 48 mi (77 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: 42.4492, -76.4492.