U.S. Frost Dates by Weather Station

NOAA station USC00304808 · New York

Frost Dates for Little Valley, NY

NOAA weather station Little Valley (USC00304808), New York · elevation 1625 ft (495 m) · hardiness zone 5b*

  • Lower-risk planting dateafter May 31only 1 spring in 10 still has a frost later
  • Typical last frostMay 1750% chance of a frost after it
  • Typical first fall frostOctober 150% chance of a frost before it
  • Frost-free season136 daystypical year, 32°F
  • Hardiness zone5bcalculated*

The year at a glance

Frost season at Little Valley, NYSpring: a frost after May 1 in 9 years out of 10, after May 17 in half of the years, after May 31 in 1 year out of 10. Fall: the first frost comes before September 18 in 1 year out of 10, before October 1 in half of the years, before October 17 in 9 years out of 10. Typical frost-free season: 136 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 17First frost ~Oct 1Frost season at Little Valley, NYSpring: a frost after May 1 in 9 years out of 10, after May 17 in half of the years, after May 31 in 1 year out of 10. Fall: the first frost comes before September 18 in 1 year out of 10, before October 1 in half of the years, before October 17 in 9 years out of 10. Typical frost-free season: 136 days.JFMAMJJASONDLast frost ~May 17First frost ~Oct 1
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 29 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 31September 18
50% (typical)May 17October 1
90% (likely)May 1October 17
Frost-free season (32°F, 50% chance)
136 days
Hard frost (28°F), last in spring, 50% chance after
May 3
Hard frost (28°F), first in fall, 50% chance before
October 15

The last 15 years (2006–2020 normals)

Typical last frost May 14 (3 days earlier than the 30-year normal), typical first fall frost October 8 (7 days later). Frost-free season 145 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 Little Valley: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 31, 20% May 27, 30% May 24, 40% May 21, 50% May 17, 60% May 14, 70% May 10, 80% May 6, 90% May 1. Observed last spring frost in recent years: 2021 May 31, 2022 May 8, 2023 May 27, 2024 June 1, 2025 June 3, 2026 May 13.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 31May 17May 12021: May 312022: May 82023: May 272024: June 12025: June 32026: May 13Fall at Little Valley: chance of a frost before this dateFall, chance of a frost before the date: 10% September 18, 20% September 23, 30% September 27, 40% September 29, 50% October 1, 60% October 4, 70% October 7, 80% October 11, 90% October 17. Observed first fall frost in recent years: 2021 October 20, 2022 September 30, 2023 October 13, 2024 October 11, 2025 October 9.Fall: first frostChance of a frost before this date10%50%90%Oct 1Sep 18Oct 1Oct 172021: October 202022: September 302023: October 132024: October 112025: October 9
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 31October 20
2022May 8September 30
2023May 27October 13
2024June 1October 11
2025June 3October 9
2026May 13season not over yet

What these dates mean

September 18 is the cautious fall date for finishing the harvest in Little Valley, carrying only a 10 % chance that a light frost has arrived earlier.

The 50% dates mark the point where a light frost is equally likely to occur later in spring or earlier in fall. The 50% date is May 17 for spring and October 1 for fall. For hard frost, the 50% dates are May 3 in spring and October 15 in fall. A cautious plan for tender crops follows the light-frost cautious dates: May 31 in spring (10 % chance of a later frost) and September 18 in fall (10 % chance of an earlier frost).

A hard frost at 28 °F can injure or kill plants that would survive a 32 °F light frost, making it the more critical temperature threshold.

How to read the probabilities

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

  • Spring: "10% after May 31" 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 18" 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 Little Valley, NYNumbered nearest stations: 1 — near Allegany, NY — 11 mi; 2 — Franklinville, NY — 19 mi; 3 — Jamestown, NY — 20 mi; 4 — Bradford 4 SW Research 5, PA — 25 mi; 5 — Bradford, PA — 32 mi.PA25 mi · 40 km1. near Allegany, NY — 11 mi12. Franklinville, NY — 19 mi23. Jamestown, NY — 20 mi34. Bradford 4 SW Research 5, PA — 25 mi45. Bradford, PA — 32 mi5
  1. near Allegany, NY 11 mi (17 km)
  2. Franklinville, NY 19 mi (30 km)
  3. Jamestown, NY 20 mi (32 km)
  4. Bradford 4 SW Research 5, PA 25 mi (40 km)
  5. Bradford, PA 32 mi (51 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: 42.2472, -78.8125.