U.S. Frost Dates by Weather Station

NOAA station USC00332067 · Ohio

Frost Dates for Dayton MCD, OH

NOAA weather station Dayton MCD (USC00332067), Ohio · elevation 720 ft (220 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 2550% chance of a frost before it
  • Frost-free season189 daystypical year, 32°F
  • Hardiness zone6bcalculated*

The year at a glance

Frost season at Dayton MCD, OHSpring: a frost after April 3 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 25 in half of the years, before November 7 in 9 years out of 10. Typical frost-free season: 189 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 18First frost ~Oct 25Frost season at Dayton MCD, OHSpring: a frost after April 3 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 25 in half of the years, before November 7 in 9 years out of 10. Typical frost-free season: 189 days.JFMAMJJASONDLast frost ~Apr 18First frost ~Oct 25
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 28 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 25
90% (likely)April 3November 7
Frost-free season (32°F, 50% chance)
189 days
Hard frost (28°F), last in spring, 50% chance after
April 6
Hard frost (28°F), first in fall, 50% chance before
November 4

The last 15 years (2006–2020 normals)

Typical last frost April 19 (1 day later than the 30-year normal), typical first fall frost October 24 (1 day earlier). Frost-free season 188 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 Dayton MCD: 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 11, 80% April 7, 90% April 3. Observed last spring frost in recent years: 2021 April 22.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 5Apr 18Apr 32021: April 22Fall at Dayton MCD: chance of a frost before this dateFall, chance of a frost before the date: 10% October 13, 20% October 17, 30% October 21, 40% October 23, 50% October 25, 60% October 27, 70% October 30, 80% November 1, 90% November 7.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 13Oct 25Nov 7
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 22incomplete record
2022incomplete recordno data
2023no datano data
2024no datano data
2025no datano data
2026no dataseason not over yet

What these dates mean

Setting out tender crops on April 3 in Dayton MCD carries a 90% chance of a light frost later, making it a gamble. The cautious date for such crops is May 5, when only a 10% chance of a later light frost remains.

The 50% date, April 18, represents a 50% chance of a light frost later than this date, while the 50% hard-frost date, April 6, is the median day for a 28 °F frost. In the fall, October 13 is the cautious date to finish harvesting tender crops, with only a 10% chance that a light frost has arrived earlier. The 50% fall light-frost date, October 25, indicates a 50% chance of a frost earlier than this date, and the 50% hard-frost date, November 4, is the median for a hard frost.

A hard frost at 28 °F can damage plant tissue more severely than a light frost at 32 °F.

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 Dayton MCD, OHNumbered nearest stations: 1 — Dayton, OH — 10 mi; 2 — Franklin, OH — 16 mi; 3 — Xenia, OH — 19 mi; 4 — Eaton, OH — 24 mi; 5 — Springfield, OH — 25 mi.OHIN25 mi · 40 km1. Dayton, OH — 10 mi12. Franklin, OH — 16 mi23. Xenia, OH — 19 mi34. Eaton, OH — 24 mi45. Springfield, OH — 25 mi5
  1. Dayton, OH 10 mi (16 km)
  2. Franklin, OH 16 mi (26 km)
  3. Xenia, OH 19 mi (30 km)
  4. Eaton, OH 24 mi (38 km)
  5. Springfield, OH 25 mi (40 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: 39.7633, -84.1911.