U.S. Frost Dates by Weather Station

NOAA station USW00094745 · New York

Frost Dates near Purchase, NY

NOAA weather station Westchester County Airport (USW00094745), New York · elevation 379 ft (116 m) · hardiness zone 7a*

Purchase is the nearest town to the station (1.8 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 April 27only 1 spring in 10 still has a frost later
  • Typical last frostApril 1250% chance of a frost after it
  • Typical first fall frostOctober 3150% chance of a frost before it
  • Frost-free season200 daystypical year, 32°F
  • Hardiness zone7acalculated*

The year at a glance

Frost season near Purchase, NYSpring: a frost after April 1 in 9 years out of 10, after April 12 in half of the years, after April 27 in 1 year out of 10. Fall: the first frost comes before October 15 in 1 year out of 10, before October 31 in half of the years, before November 14 in 9 years out of 10. Typical frost-free season: 200 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 12First frost ~Oct 31Frost season near Purchase, NYSpring: a frost after April 1 in 9 years out of 10, after April 12 in half of the years, after April 27 in 1 year out of 10. Fall: the first frost comes before October 15 in 1 year out of 10, before October 31 in half of the years, before November 14 in 9 years out of 10. Typical frost-free season: 200 days.JFMAMJJASONDLast frost ~Apr 12First frost ~Oct 31
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 28 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)April 27October 15
50% (typical)April 12October 31
90% (likely)April 1November 14
Frost-free season (32°F, 50% chance)
200 days
Hard frost (28°F), last in spring, 50% chance after
April 1
Hard frost (28°F), first in fall, 50% chance before
November 13

The last 15 years (2006–2020 normals)

Typical last frost April 10 (2 days earlier than the 30-year normal), typical first fall frost November 1 (1 day later). Frost-free season 204 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 Purchase: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 27, 20% April 21, 30% April 18, 40% April 15, 50% April 12, 60% April 10, 70% April 7, 80% April 5, 90% April 1. Observed last spring frost in recent years: 2021 April 3, 2022 April 18, 2023 April 8, 2024 March 25, 2025 April 10, 2026 April 21.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1Apr 27Apr 12Apr 12021: April 32022: April 182023: April 82024: March 252025: April 102026: April 21Fall near Purchase: chance of a frost before this dateFall, chance of a frost before the date: 10% October 15, 20% October 21, 30% October 24, 40% October 28, 50% October 31, 60% November 2, 70% November 5, 80% November 9, 90% November 14. Observed first fall frost in recent years: 2021 November 4, 2022 November 14, 2023 November 2, 2024 November 13.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 15Oct 31Nov 142021: November 42022: November 142023: November 22024: November 13
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 3November 4
2022April 18November 14
2023April 8November 2
2024March 25November 13
2025April 10incomplete record
2026April 21season not over yet

What these dates mean

April 27 is the cautious spring date for the Purchase area, a point when only a 10 % chance of a light frost remains later, allowing a gardener to set out tender crops.

The 50% date is April 12 and the 50% date is October 31; each carries a 50 % chance of a frost later (April 12) or earlier (October 31). The cautious fall date is October 15, when there is only a 10 % chance a light frost has arrived, making it the prudent time to finish harvesting tender crops.

Hard-frost dates—April 1 in spring and November 13 in fall—mark the 50 % odds for 28 °F, a temperature that can harm plants that survive a 32 °F frost, so hard frost is a more critical risk. In the 28-year record the two 32°F 50% dates are 200 days apart, defining the frost-free window for this station.

How to read the probabilities

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

  • Spring: "10% after April 27" 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 15" 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 Purchase, NYNumbered nearest stations: 1 — Yorktown Heights, NY — 15 mi; 2 — New York (LaGuardia Airport), NY — 22 mi; 3 — New York (Central Park), NY — 24 mi; 4 — New York (JFK Airport), NY — 30 mi; 5 — near Bridgeport, CT — 31 mi.NJCTPA25 mi · 40 km1. Yorktown Heights, NY — 15 mi12. New York (LaGuardia Airport), NY — 22 mi23. New York (Central Park), NY — 24 mi34. New York (JFK Airport), NY — 30 mi45. near Bridgeport, CT — 31 mi5
  1. Yorktown Heights, NY 15 mi (23 km)
  2. New York (LaGuardia Airport), NY 22 mi (35 km)
  3. New York (Central Park), NY 24 mi (39 km)
  4. New York (JFK Airport), NY 30 mi (48 km)
  5. near Bridgeport, CT 31 mi (50 km)

Sources

* Hardiness zone 7a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 41.0669, -73.7075.