U.S. Frost Dates by Weather Station

NOAA station USC00300331 · New York

Frost Dates near Union Springs, NY

NOAA weather station Aurora Research Farm (USC00300331), New York · elevation 830 ft (253 m) · hardiness zone 6a*

Union Springs is the nearest town to the station (7.5 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 16only 1 spring in 10 still has a frost later
  • Typical last frostMay 150% chance of a frost after it
  • Typical first fall frostOctober 2150% chance of a frost before it
  • Frost-free season172 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season near Union Springs, NYSpring: a frost after April 17 in 9 years out of 10, after May 1 in half of the years, after May 16 in 1 year out of 10. Fall: the first frost comes before October 4 in 1 year out of 10, before October 21 in half of the years, before November 5 in 9 years out of 10. Typical frost-free season: 172 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 1First frost ~Oct 21Frost season near Union Springs, NYSpring: a frost after April 17 in 9 years out of 10, after May 1 in half of the years, after May 16 in 1 year out of 10. Fall: the first frost comes before October 4 in 1 year out of 10, before October 21 in half of the years, before November 5 in 9 years out of 10. Typical frost-free season: 172 days.JFMAMJJASONDLast frost ~May 1First frost ~Oct 21
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 27 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 16October 4
50% (typical)May 1October 21
90% (likely)April 17November 5
Frost-free season (32°F, 50% chance)
172 days
Hard frost (28°F), last in spring, 50% chance after
April 19
Hard frost (28°F), first in fall, 50% chance before
November 3

The last 15 years (2006–2020 normals)

Typical last frost April 29 (2 days earlier than the 30-year normal), typical first fall frost October 24 (3 days later). Frost-free season 178 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 Union Springs: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 16, 20% May 10, 30% May 6, 40% May 3, 50% May 1, 60% April 28, 70% April 25, 80% April 22, 90% April 17. Observed last spring frost in recent years: 2021 April 27, 2022 April 30, 2023 May 18, 2024 April 28.Spring: last frostChance of a frost after this date10%50%90%May 1May 16May 1Apr 172021: April 272022: April 302023: May 182024: April 28Fall near Union Springs: chance of a frost before this dateFall, chance of a frost before the date: 10% October 4, 20% October 9, 30% October 13, 40% October 18, 50% October 21, 60% October 24, 70% October 27, 80% November 1, 90% November 5. Observed first fall frost in recent years: 2021 November 4, 2022 October 28, 2023 November 2.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 4Oct 21Nov 52021: November 42022: October 282023: November 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
2021April 27November 4
2022April 30October 28
2023May 18November 2
2024April 28no data
2025no datano data
2026no dataseason not over yet

What these dates mean

October 4 is the cautious fall date for the Union Springs area, indicating a 10 % chance that a light frost has already arrived and marking a good time to finish harvesting tender crops. In spring the cautious date for setting out tender crops is May 16, when there is only a 10 % chance of a light frost occurring later than that day.

May 1 is the 50 % date for light frost in spring, meaning there is a 50 % chance of a frost later than this date, while October 21 is the 50 % date for light frost in fall, meaning there is a 50 % chance of a frost earlier than this date. The median hard-frost dates are April 19 in spring and November 3 in fall; these are the points at which a 28 °F frost is equally likely to have occurred or not.

A hard frost at 28 °F can damage plant tissues more severely than a light frost at 32 °F, so it is a more critical threshold for gardeners.

How to read the probabilities

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

  • Spring: "10% after May 16" 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 4" 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 Union Springs, NYNumbered nearest stations: 1 — Geneva, NY — 21 mi; 2 — near Ithaca, NY — 22 mi; 3 — Canandaigua, NY — 32 mi; 4 — near Syracuse, NY — 38 mi; 5 — Sodus, NY — 41 mi.25 mi · 40 km1. Geneva, NY — 21 mi12. near Ithaca, NY — 22 mi23. Canandaigua, NY — 32 mi34. near Syracuse, NY — 38 mi45. Sodus, NY — 41 mi5
  1. Geneva, NY 21 mi (34 km)
  2. near Ithaca, NY 22 mi (36 km)
  3. Canandaigua, NY 32 mi (52 km)
  4. near Syracuse, NY 38 mi (62 km)
  5. Sodus, NY 41 mi (66 km)

Sources

* Hardiness zone 6a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 42.7339, -76.6592.