U.S. Frost Dates by Weather Station

NOAA station USC00333780 · Ohio

Frost Dates for Hiram, OH

NOAA weather station Hiram (USC00333780), Ohio · elevation 1230 ft (375 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 18only 1 spring in 10 still has a frost later
  • Typical last frostMay 150% chance of a frost after it
  • Typical first fall frostOctober 2050% chance of a frost before it
  • Frost-free season170 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Hiram, OHSpring: a frost after April 18 in 9 years out of 10, after May 1 in half of the years, after May 18 in 1 year out of 10. Fall: the first frost comes before October 5 in 1 year out of 10, before October 20 in half of the years, before November 1 in 9 years out of 10. Typical frost-free season: 170 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 1First frost ~Oct 20Frost season at Hiram, OHSpring: a frost after April 18 in 9 years out of 10, after May 1 in half of the years, after May 18 in 1 year out of 10. Fall: the first frost comes before October 5 in 1 year out of 10, before October 20 in half of the years, before November 1 in 9 years out of 10. Typical frost-free season: 170 days.JFMAMJJASONDLast frost ~May 1First frost ~Oct 20
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 18October 5
50% (typical)May 1October 20
90% (likely)April 18November 1
Frost-free season (32°F, 50% chance)
170 days
Hard frost (28°F), last in spring, 50% chance after
April 21
Hard frost (28°F), first in fall, 50% chance before
November 1

The last 15 years (2006–2020 normals)

Typical last frost May 1 (same as the 30-year normal), typical first fall frost October 21 (1 day later). Frost-free season 172 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 Hiram: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 18, 20% May 11, 30% May 7, 40% May 4, 50% May 1, 60% April 28, 70% April 26, 80% April 22, 90% April 18. Observed last spring frost in recent years: 2021 May 13, 2022 April 30, 2023 May 18, 2024 April 26, 2025 April 18, 2026 May 3.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 18May 1Apr 182021: May 132022: April 302023: May 182024: April 262025: April 182026: May 3Fall at Hiram: chance of a frost before this dateFall, chance of a frost before the date: 10% October 5, 20% October 10, 30% October 14, 40% October 17, 50% October 20, 60% October 22, 70% October 25, 80% October 28, 90% November 1. Observed first fall frost in recent years: 2021 November 3, 2022 October 19, 2023 October 23, 2024 October 17, 2025 October 27.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 5Oct 20Nov 12021: November 32022: October 192023: October 232024: October 172025: October 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. ◆ 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 13November 3
2022April 30October 19
2023May 18October 23
2024April 26October 17
2025April 18October 27
2026May 3season not over yet

What these dates mean

The 170 days between the 50% dates in Hiram mark the interval when a light frost is less likely than not, giving gardeners a span to schedule most planting, maintenance and harvest tasks.

The 50% dates—May 1 for spring and October 20 for fall—show the point at which a light frost has an even chance of occurring before or after, so the period between them is the core growing season. Hard-frost 50% dates fall on April 21 and November 1; hard frosts matter more than light frosts because 28 °F can kill tissue that survives a 32 °F event.

For tender crops the cautious spring date is May 18, when there is only a 10% chance of a later frost, and the cautious fall date is October 5, with a 10% chance of an earlier frost; planting outside those windows raises the 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 18" 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 5" 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 Hiram, OHNumbered nearest stations: 1 — Warren, OH — 13 mi; 2 — Youngstown, OH — 18 mi; 3 — Chardon, OH — 21 mi; 4 — Jamestown, PA — 31 mi; 5 — Dorset, OH — 32 mi.OHPANY25 mi · 40 km1. Warren, OH — 13 mi12. Youngstown, OH — 18 mi23. Chardon, OH — 21 mi34. Jamestown, PA — 31 mi45. Dorset, OH — 32 mi5
  1. Warren, OH 13 mi (21 km)
  2. Youngstown, OH 18 mi (29 km)
  3. Chardon, OH 21 mi (34 km)
  4. Jamestown, PA 31 mi (50 km)
  5. Dorset, 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: 41.3072, -81.0133.