U.S. Frost Dates by Weather Station

NOAA station USC00338769 · Ohio

Frost Dates for Warren, OH

NOAA weather station Warren 3 S (USC00338769), Ohio · elevation 900 ft (274 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 25only 1 spring in 10 still has a frost later
  • Typical last frostMay 850% chance of a frost after it
  • Typical first fall frostOctober 1250% chance of a frost before it
  • Frost-free season157 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Warren, OHSpring: a frost after April 23 in 9 years out of 10, after May 8 in half of the years, after May 25 in 1 year out of 10. Fall: the first frost comes before September 30 in 1 year out of 10, before October 12 in half of the years, before October 26 in 9 years out of 10. Typical frost-free season: 157 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 8First frost ~Oct 12Frost season at Warren, OHSpring: a frost after April 23 in 9 years out of 10, after May 8 in half of the years, after May 25 in 1 year out of 10. Fall: the first frost comes before September 30 in 1 year out of 10, before October 12 in half of the years, before October 26 in 9 years out of 10. Typical frost-free season: 157 days.JFMAMJJASONDLast frost ~May 8First frost ~Oct 12
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 30 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 25September 30
50% (typical)May 8October 12
90% (likely)April 23October 26
Frost-free season (32°F, 50% chance)
157 days
Hard frost (28°F), last in spring, 50% chance after
April 27
Hard frost (28°F), first in fall, 50% chance before
October 26

The last 15 years (2006–2020 normals)

Typical last frost May 6 (2 days earlier than the 30-year normal), typical first fall frost October 18 (6 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 Warren: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 25, 20% May 19, 30% May 15, 40% May 11, 50% May 8, 60% May 5, 70% May 1, 80% April 29, 90% April 23. Observed last spring frost in recent years: 2021 May 14, 2022 April 29, 2023 May 20, 2024 April 27, 2025 May 5, 2026 May 11.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 25May 8Apr 232021: May 142022: April 292023: May 202024: April 272025: May 52026: May 11Fall at Warren: chance of a frost before this dateFall, chance of a frost before the date: 10% September 30, 20% October 3, 30% October 6, 40% October 9, 50% October 12, 60% October 14, 70% October 18, 80% October 22, 90% October 26. Observed first fall frost in recent years: 2021 November 3, 2022 October 9, 2023 October 23, 2024 October 10, 2025 October 17.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 30Oct 12Oct 262021: November 32022: October 92023: October 232024: October 102025: October 17
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 14November 3
2022April 29October 9
2023May 20October 23
2024April 27October 10
2025May 5October 17
2026May 11season not over yet

What these dates mean

The 157 days between the 50% dates in Warren — May 8 and October 12 — mark the stretch where a light frost has an even chance of occurring before or after each date, framing the typical frost-free window for the location. During those 157 days the probability of reaching 32 °F drops below fifty percent, giving gardeners a reliable span for most activities.

The cautious spring date is May 25, a 10 %-chance point for setting out tender crops, while planting on April 23 would be a gamble with a 90 % chance of a frost later. In the fall, the cautious date is September 30, offering a 10 % chance to finish harvesting tender crops; waiting until October 26 carries a 90 % chance of a frost earlier.

The hard-frost 50% dates are April 27 and October 26. A hard frost at 28 °F can damage plants that survive a 32 °F light frost, so it matters more.

How to read the probabilities

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

  • Spring: "10% after May 25" 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 30" 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 Warren, OHNumbered nearest stations: 1 — Youngstown, OH — 8 mi; 2 — Hiram, OH — 13 mi; 3 — New Castle, PA — 27 mi; 4 — Jamestown, PA — 27 mi; 5 — Chardon, OH — 33 mi.OHPA25 mi · 40 km1. Youngstown, OH — 8 mi12. Hiram, OH — 13 mi23. New Castle, PA — 27 mi34. Jamestown, PA — 27 mi45. Chardon, OH — 33 mi5
  1. Youngstown, OH 8 mi (13 km)
  2. Hiram, OH 13 mi (21 km)
  3. New Castle, PA 27 mi (43 km)
  4. Jamestown, PA 27 mi (44 km)
  5. Chardon, OH 33 mi (53 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: 41.2019, -80.8106.