U.S. Frost Dates by Weather Station

NOAA station USW00094790 · New York

Frost Dates for Watertown (Airport), NY

NOAA weather station Watertown International Airport (USW00094790), New York · elevation 318 ft (97 m) · hardiness zone 5a*

  • 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 150% chance of a frost before it
  • Frost-free season140 daystypical year, 32°F
  • Hardiness zone5acalculated*

The year at a glance

Frost season at Watertown (Airport), NYSpring: a frost after April 29 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 16 in 1 year out of 10, before October 1 in half of the years, before October 13 in 9 years out of 10. Typical frost-free season: 140 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 11First frost ~Oct 1Frost season at Watertown (Airport), NYSpring: a frost after April 29 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 16 in 1 year out of 10, before October 1 in half of the years, before October 13 in 9 years out of 10. Typical frost-free season: 140 days.JFMAMJJASONDLast frost ~May 11First 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.Today

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 16
50% (typical)May 11October 1
90% (likely)April 29October 13
Frost-free season (32°F, 50% chance)
140 days
Hard frost (28°F), last in spring, 50% chance after
April 30
Hard frost (28°F), first in fall, 50% chance before
October 11

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 5 (4 days later). Frost-free season 148 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 Watertown (Airport): chance of a frost after this dateSpring, chance of a frost after the date: 10% May 26, 20% May 21, 30% May 17, 40% May 14, 50% May 11, 60% May 8, 70% May 6, 80% May 2, 90% April 29. Observed last spring frost in recent years: 2021 May 1, 2022 May 8, 2023 May 25, 2024 April 26, 2025 April 28, 2026 May 22.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 26May 11Apr 292021: May 12022: May 82023: May 252024: April 262025: April 282026: May 22Fall at Watertown (Airport): chance of a frost before this dateFall, chance of a frost before the date: 10% September 16, 20% September 21, 30% September 24, 40% September 27, 50% October 1, 60% October 2, 70% October 5, 80% October 9, 90% October 13. Observed first fall frost in recent years: 2021 October 23, 2022 October 3, 2023 October 13, 2024 October 9, 2025 September 20.Fall: first frostChance of a frost before this date10%50%90%Oct 1Sep 16Oct 1Oct 132021: October 232022: October 32023: October 132024: October 92025: 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 1October 23
2022May 8October 3
2023May 25October 13
2024April 26October 9
2025April 28September 20
2026May 22season not over yet

What these dates mean

May 26 is the cautious spring date for setting out tender crops in Watertown (Airport). With only a 10 % chance of a light frost after that day, a gardener can schedule planting with minimal risk. The 50 % date, May 11, marks the point where a frost is equally likely to happen later, and the hard-frost 50 % date is April 30.

In the fall, September 16 serves as the cautious date to finish harvesting tender crops, because there is only a 10 % chance that a light frost has already arrived. The 50 % date, October 1, indicates an even chance of a frost occurring earlier, while the hard-frost 50 % date is October 11.

Hard frost at 28 °F can injure plants that survive a light frost at 32 °F, so it represents a higher threat to garden productivity.

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 16" 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 Watertown (Airport), NYNumbered nearest stations: 1 — Watertown, NY — 7 mi; 2 — Lowville, NY — 30 mi; 3 — Gouverneur, NY — 36 mi; 4 — Oswego, NY — 45 mi; 5 — Boonville, NY — 50 mi.25 mi · 40 km1. Watertown, NY — 7 mi12. Lowville, NY — 30 mi23. Gouverneur, NY — 36 mi34. Oswego, NY — 45 mi45. Boonville, NY — 50 mi5
  1. Watertown, NY 7 mi (12 km)
  2. Lowville, NY 30 mi (49 km)
  3. Gouverneur, NY 36 mi (57 km)
  4. Oswego, NY 45 mi (73 km)
  5. Boonville, NY 50 mi (81 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: 43.9922, -76.0217.