U.S. Frost Dates by Weather Station

NOAA station USC00339312 · Ohio

Frost Dates for Wooster, OH

NOAA weather station Wooster Experiment Station (USC00339312), Ohio · elevation 1020 ft (311 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 18only 1 spring in 10 still has a frost later
  • Typical last frostApril 3050% chance of a frost after it
  • Typical first fall frostOctober 1250% chance of a frost before it
  • Frost-free season163 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Wooster, OHSpring: a frost after April 17 in 9 years out of 10, after April 30 in half of the years, after May 18 in 1 year out of 10. Fall: the first frost comes before September 29 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: 163 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 30First frost ~Oct 12Frost season at Wooster, OHSpring: a frost after April 17 in 9 years out of 10, after April 30 in half of the years, after May 18 in 1 year out of 10. Fall: the first frost comes before September 29 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: 163 days.JFMAMJJASONDLast frost ~Apr 30First 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 18September 29
50% (typical)April 30October 12
90% (likely)April 17October 26
Frost-free season (32°F, 50% chance)
163 days
Hard frost (28°F), last in spring, 50% chance after
April 20
Hard frost (28°F), first in fall, 50% chance before
October 24

The last 15 years (2006–2020 normals)

Typical last frost April 30 (same as the 30-year normal), typical first fall frost October 19 (7 days later). Frost-free season 170 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 Wooster: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 18, 20% May 12, 30% May 8, 40% May 4, 50% April 30, 60% April 28, 70% April 25, 80% April 22, 90% April 17. Observed last spring frost in recent years: 2021 May 12.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 18Apr 30Apr 172021: May 12Fall at Wooster: chance of a frost before this dateFall, chance of a frost before the date: 10% September 29, 20% October 3, 30% October 6, 40% October 10, 50% October 12, 60% October 15, 70% October 18, 80% October 21, 90% October 26. Observed first fall frost in recent years: 2021 October 20.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 29Oct 12Oct 262021: October 20
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 12October 20
2022incomplete recordno data
2023no datano data
2024no datano data
2025no datano data
2026no dataseason not over yet

What these dates mean

May 18 is the cautious spring date for setting out tender crops in Wooster; only a 10 % chance remains that a light frost will occur later.

The 50 % date is April 30, which marks an even-odds point for a light frost later in spring, and the 50 % date is October 12, the even-odds point for a light frost earlier in fall. September 29 is the cautious fall date for finishing harvest of tender crops, holding a 10 % chance that a frost has arrived earlier. The period between the two 32 °F 50 % dates spans 163 days, according to the 30-year record.

Hard frost at 28 °F, represented by the median dates April 20 in spring and October 24 in fall, matters more because it can injure plants that would survive a 32 °F light frost.

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 September 29" 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 Wooster, OHNumbered nearest stations: 1 — Millersburg, OH — 17 mi; 2 — near Akron, OH — 27 mi; 3 — Danville, OH — 31 mi; 4 — near Mansfield, OH — 32 mi; 5 — Dennison, OH — 40 mi.OH25 mi · 40 km1. Millersburg, OH — 17 mi12. near Akron, OH — 27 mi23. Danville, OH — 31 mi34. near Mansfield, OH — 32 mi45. Dennison, OH — 40 mi5
  1. Millersburg, OH 17 mi (27 km)
  2. near Akron, OH 27 mi (43 km)
  3. Danville, OH 31 mi (50 km)
  4. near Mansfield, OH 32 mi (51 km)
  5. Dennison, OH 40 mi (64 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: 40.7833, -81.9167.