U.S. Frost Dates by Weather Station

NOAA station USC00334927 · Ohio

Frost Dates for Marietta, OH

NOAA weather station Marietta WWTP (USC00334927), Ohio · elevation 610 ft (186 m) · hardiness zone 6b*

  • Lower-risk planting dateafter May 4only 1 spring in 10 still has a frost later
  • Typical last frostApril 1850% chance of a frost after it
  • Typical first fall frostOctober 2750% chance of a frost before it
  • Frost-free season191 daystypical year, 32°F
  • Hardiness zone6bcalculated*

The year at a glance

Frost season at Marietta, OHSpring: a frost after April 5 in 9 years out of 10, after April 18 in half of the years, after May 4 in 1 year out of 10. Fall: the first frost comes before October 13 in 1 year out of 10, before October 27 in half of the years, before November 6 in 9 years out of 10. Typical frost-free season: 191 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 18First frost ~Oct 27Frost season at Marietta, OHSpring: a frost after April 5 in 9 years out of 10, after April 18 in half of the years, after May 4 in 1 year out of 10. Fall: the first frost comes before October 13 in 1 year out of 10, before October 27 in half of the years, before November 6 in 9 years out of 10. Typical frost-free season: 191 days.JFMAMJJASONDLast frost ~Apr 18First frost ~Oct 27
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 4October 13
50% (typical)April 18October 27
90% (likely)April 5November 6
Frost-free season (32°F, 50% chance)
191 days
Hard frost (28°F), last in spring, 50% chance after
April 5
Hard frost (28°F), first in fall, 50% chance before
November 5

The last 15 years (2006–2020 normals)

Typical last frost April 16 (2 days earlier than the 30-year normal), typical first fall frost October 30 (3 days later). Frost-free season 197 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 Marietta: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 4, 20% April 29, 30% April 24, 40% April 21, 50% April 18, 60% April 16, 70% April 13, 80% April 9, 90% April 5. Observed last spring frost in recent years: 2021 April 23, 2022 April 28, 2023 April 25, 2024 April 22, 2025 April 17, 2026 April 21.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 4Apr 18Apr 52021: April 232022: April 282023: April 252024: April 222025: April 172026: April 21Fall at Marietta: chance of a frost before this dateFall, chance of a frost before the date: 10% October 13, 20% October 17, 30% October 20, 40% October 24, 50% October 27, 60% October 30, 70% November 1, 80% November 3, 90% November 6. Observed first fall frost in recent years: 2021 November 3, 2022 October 20, 2023 October 23, 2024 October 28, 2025 October 25.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 13Oct 27Nov 62021: November 32022: October 202023: October 232024: October 282025: October 25
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 23November 3
2022April 28October 20
2023April 25October 23
2024April 22October 28
2025April 17October 25
2026April 21season not over yet

What these dates mean

May 4 is the cautious spring date in Marietta, offering a gardener a 10% chance that a light frost will occur later and therefore marking a reliable point to set out tender crops.

The 50% date in spring is April 18; at that point there is an even chance of a light frost occurring later, while the 50% date in fall is October 27 with an even chance of a light frost occurring earlier. The cautious fall date is October 13, when only a 10% chance exists that a light frost has already arrived, giving a good target to finish harvesting tender crops. The early-spring gamble date is April 5 and the late-fall gamble date is November 6, each carrying a 90% chance of a frost.

Hard frosts at 28°F are more damaging than light frosts at 32°F because they can injure or kill plant tissue that survives a milder freeze. The median hard-frost dates are April 5 and November 5, indicating the point at which a 28°F freeze is equally likely.

How to read the probabilities

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

  • Spring: "10% after May 4" 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 Marietta, OHNumbered nearest stations: 1 — near Williamstown, WV — 4 mi; 2 — Parkersburg, WV — 11 mi; 3 — Middlebourne, WV — 31 mi; 4 — Hannibal Locks & Dam, OH — 35 mi; 5 — West Union, WV — 36 mi.OHPA25 mi · 40 km1. near Williamstown, WV — 4 mi12. Parkersburg, WV — 11 mi23. Middlebourne, WV — 31 mi34. Hannibal Locks & Dam, OH — 35 mi45. West Union, WV — 36 mi5
  1. near Williamstown, WV 4 mi (7 km)
  2. Parkersburg, WV 11 mi (18 km)
  3. Middlebourne, WV 31 mi (50 km)
  4. Hannibal Locks & Dam, OH 35 mi (56 km)
  5. West Union, WV 36 mi (59 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: 39.4086, -81.4328.