U.S. Frost Dates by Weather Station

NOAA station USC00332251 · Ohio

Frost Dates for Dorset, OH

NOAA weather station Dorset (USC00332251), Ohio · elevation 980 ft (299 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 27only 1 spring in 10 still has a frost later
  • Typical last frostMay 1050% chance of a frost after it
  • Typical first fall frostOctober 1050% chance of a frost before it
  • Frost-free season154 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Dorset, OHSpring: a frost after April 25 in 9 years out of 10, after May 10 in half of the years, after May 27 in 1 year out of 10. Fall: the first frost comes before September 26 in 1 year out of 10, before October 10 in half of the years, before October 27 in 9 years out of 10. Typical frost-free season: 154 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 10First frost ~Oct 10Frost season at Dorset, OHSpring: a frost after April 25 in 9 years out of 10, after May 10 in half of the years, after May 27 in 1 year out of 10. Fall: the first frost comes before September 26 in 1 year out of 10, before October 10 in half of the years, before October 27 in 9 years out of 10. Typical frost-free season: 154 days.JFMAMJJASONDLast frost ~May 10First frost ~Oct 10
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 28 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 27September 26
50% (typical)May 10October 10
90% (likely)April 25October 27
Frost-free season (32°F, 50% chance)
154 days
Hard frost (28°F), last in spring, 50% chance after
April 28
Hard frost (28°F), first in fall, 50% chance before
October 26

The last 15 years (2006–2020 normals)

Typical last frost May 8 (2 days earlier than the 30-year normal), typical first fall frost October 18 (8 days later). Frost-free season 163 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 Dorset: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 27, 20% May 22, 30% May 18, 40% May 14, 50% May 10, 60% May 6, 70% May 3, 80% April 30, 90% April 25.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 27May 10Apr 25Fall at Dorset: chance of a frost before this dateFall, chance of a frost before the date: 10% September 26, 20% October 1, 30% October 4, 40% October 6, 50% October 10, 60% October 13, 70% October 16, 80% October 21, 90% October 27.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 26Oct 10Oct 27
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.

What these dates mean

The 154 days between the 50% dates in Dorset — May 10 and October 10 — frame the period when a light frost is as likely as not, giving gardeners a clear window for frost-sensitive activities. The 50% date in spring, May 10, marks an even chance that a frost could still occur later, while the 50% date in fall, October 10, marks an even chance that a frost could have already arrived earlier. This median timing helps gardeners assess risk without implying safety.

For a cautious approach, the spring light-frost date with a 10 % chance of a later frost is May 27, and the fall cautious date with a 10 % chance of an earlier frost is September 26; planting or harvesting around those dates reduces the likelihood of unexpected frost damage. The hard-frost 50% dates are April 28 and October 26, and a hard frost at 28 °F can injure or kill plants 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 27" 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 26" 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 Dorset, OHNumbered nearest stations: 1 — Linesville, PA — 13 mi; 2 — Jamestown, PA — 16 mi; 3 — Chardon, OH — 28 mi; 4 — Youngstown, OH — 30 mi; 5 — Hiram, OH — 32 mi.OHPA25 mi · 40 km1. Linesville, PA — 13 mi12. Jamestown, PA — 16 mi23. Chardon, OH — 28 mi34. Youngstown, OH — 30 mi45. Hiram, OH — 32 mi5
  1. Linesville, PA 13 mi (21 km)
  2. Jamestown, PA 16 mi (26 km)
  3. Chardon, OH 28 mi (45 km)
  4. Youngstown, OH 30 mi (48 km)
  5. Hiram, OH 32 mi (51 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: 41.6833, -80.6667.