U.S. Frost Dates by Weather Station

NOAA station USC00151998 · Kentucky

Frost Dates for Cynthiana, KY

NOAA weather station Cynthiana (USC00151998), Kentucky · elevation 700 ft (213 m) · hardiness zone 6b*

  • Lower-risk planting dateafter May 5only 1 spring in 10 still has a frost later
  • Typical last frostApril 1850% chance of a frost after it
  • Typical first fall frostOctober 2350% chance of a frost before it
  • Frost-free season188 daystypical year, 32°F
  • Hardiness zone6bcalculated*

The year at a glance

Frost season at Cynthiana, KYSpring: a frost after April 2 in 9 years out of 10, after April 18 in half of the years, after May 5 in 1 year out of 10. Fall: the first frost comes before October 13 in 1 year out of 10, before October 23 in half of the years, before November 4 in 9 years out of 10. Typical frost-free season: 188 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 18First frost ~Oct 23Frost season at Cynthiana, KYSpring: a frost after April 2 in 9 years out of 10, after April 18 in half of the years, after May 5 in 1 year out of 10. Fall: the first frost comes before October 13 in 1 year out of 10, before October 23 in half of the years, before November 4 in 9 years out of 10. Typical frost-free season: 188 days.JFMAMJJASONDLast frost ~Apr 18First frost ~Oct 23
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 26 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 5October 13
50% (typical)April 18October 23
90% (likely)April 2November 4
Frost-free season (32°F, 50% chance)
188 days
Hard frost (28°F), last in spring, 50% chance after
April 5
Hard frost (28°F), first in fall, 50% chance before
November 2

The last 15 years (2006–2020 normals)

Typical last frost April 18 (same as the 30-year normal), typical first fall frost October 26 (3 days later). Frost-free season 191 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 Cynthiana: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 5, 20% April 30, 30% April 25, 40% April 21, 50% April 18, 60% April 15, 70% April 12, 80% April 8, 90% April 2. Observed last spring frost in recent years: 2021 April 24, 2022 April 11, 2023 April 26, 2024 April 23, 2025 April 13, 2026 May 4.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 5Apr 18Apr 22021: April 242022: April 112023: April 262024: April 232025: April 132026: May 4Fall at Cynthiana: chance of a frost before this dateFall, chance of a frost before the date: 10% October 13, 20% October 16, 30% October 19, 40% October 22, 50% October 23, 60% October 26, 70% October 29, 80% October 31, 90% November 4. Observed first fall frost in recent years: 2021 November 3, 2022 October 9, 2023 October 31, 2024 October 28, 2025 October 24.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 13Oct 23Nov 42021: November 32022: October 92023: October 312024: October 282025: October 24
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 24November 3
2022April 11October 9
2023April 26October 31
2024April 23October 28
2025April 13October 24
2026May 4season not over yet

What these dates mean

188 days separate the 50% light-frost dates of April 18 and October 23, framing the core growing interval for Cynthiana. The 50% light-frost dates mean there is a 50% chance of a frost later than April 18 in spring and a 50% chance of a frost earlier than October 23 in fall.

For a cautious spring plan, the LATE date of May 5 carries only a 10% chance of a frost later, while planting on April 2 carries a 90% chance and is a gamble. In fall, the EARLY date of October 13 holds a 10% chance of a frost earlier, whereas November 4 represents a 90% chance and is a gamble. The 50% hard-frost dates are April 5 and November 2; a hard frost at 28 °F can injure plants that survive a light frost at 32 °F, making those dates important markers of severe cold risk.

How to read the probabilities

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

  • Spring: "10% after May 5" 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 13" 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 Cynthiana, KYNumbered nearest stations: 1 — near Lexington, KY — 28 mi; 2 — near Morehead, KY — 45 mi; 3 — near Burlington, KY — 50 mi; 4 — near Cincinnati, OH — 51 mi; 5 — Cheviot, OH — 56 mi.OHIN25 mi · 40 km1. near Lexington, KY — 28 mi12. near Morehead, KY — 45 mi23. near Burlington, KY — 50 mi34. near Cincinnati, OH — 51 mi45. Cheviot, OH — 56 mi5
  1. near Lexington, KY 28 mi (46 km)
  2. near Morehead, KY 45 mi (73 km)
  3. near Burlington, KY 50 mi (81 km)
  4. near Cincinnati, OH 51 mi (81 km)
  5. Cheviot, OH 56 mi (91 km)

Sources

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

Station coordinates: 38.3769, -84.3031.