U.S. Frost Dates by Weather Station

NOAA station USC00338822 · Ohio

Frost Dates for Wauseon, OH

NOAA weather station Wauseon WTP (USC00338822), Ohio · elevation 750 ft (229 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 16only 1 spring in 10 still has a frost later
  • Typical last frostApril 2950% chance of a frost after it
  • Typical first fall frostOctober 1650% chance of a frost before it
  • Frost-free season170 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Wauseon, OHSpring: a frost after April 14 in 9 years out of 10, after April 29 in half of the years, after May 16 in 1 year out of 10. Fall: the first frost comes before September 30 in 1 year out of 10, before October 16 in half of the years, before October 31 in 9 years out of 10. Typical frost-free season: 170 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 29First frost ~Oct 16Frost season at Wauseon, OHSpring: a frost after April 14 in 9 years out of 10, after April 29 in half of the years, after May 16 in 1 year out of 10. Fall: the first frost comes before September 30 in 1 year out of 10, before October 16 in half of the years, before October 31 in 9 years out of 10. Typical frost-free season: 170 days.JFMAMJJASONDLast frost ~Apr 29First frost ~Oct 16
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 29 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 16September 30
50% (typical)April 29October 16
90% (likely)April 14October 31
Frost-free season (32°F, 50% chance)
170 days
Hard frost (28°F), last in spring, 50% chance after
April 16
Hard frost (28°F), first in fall, 50% chance before
October 29

The last 15 years (2006–2020 normals)

Typical last frost April 24 (5 days earlier than the 30-year normal), typical first fall frost October 22 (6 days later). Frost-free season 179 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 Wauseon: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 16, 20% May 9, 30% May 4, 40% May 1, 50% April 29, 60% April 25, 70% April 22, 80% April 18, 90% April 14. Observed last spring frost in recent years: 2021 May 15, 2022 April 29, 2023 April 28, 2024 April 26, 2025 April 17, 2026 April 21.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 16Apr 29Apr 142021: May 152022: April 292023: April 282024: April 262025: April 172026: April 21Fall at Wauseon: chance of a frost before this dateFall, chance of a frost before the date: 10% September 30, 20% October 6, 30% October 9, 40% October 13, 50% October 16, 60% October 19, 70% October 23, 80% October 26, 90% October 31. Observed first fall frost in recent years: 2021 October 24, 2022 October 8, 2023 October 23, 2024 October 17.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 30Oct 16Oct 312021: October 242022: October 82023: October 232024: 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 15October 24
2022April 29October 8
2023April 28October 23
2024April 26October 17
2025April 17incomplete record
2026April 21season not over yet

What these dates mean

May 16 is the cautious spring date in Wauseon, and it signals when a gardener can set out tender crops with only a 10 % chance of a light frost occurring later.

The 50% date is April 29; there is a 50 % chance of a frost later than this date, while September 30 serves as the cautious fall date, marking when a gardener can finish harvesting tender crops with only a 10 % chance of a light frost having arrived earlier. The 50% date is October 16; there is a 50 % chance of a frost earlier than this date.

Hard frost at 28 °F can cause more severe damage than a light frost at 32 °F, so the 50% hard-frost dates—April 16 and October 29—show when severe freezing becomes a real possibility.

How to read the probabilities

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

  • Spring: "10% after May 16" 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 Wauseon, OHNumbered nearest stations: 1 — near Toledo, OH — 18 mi; 2 — Defiance, OH — 21 mi; 3 — Adrian, MI — 28 mi; 4 — Bowling Green, OH — 29 mi; 5 — Hillsdale, MI — 39 mi.MIIN25 mi · 40 km1. near Toledo, OH — 18 mi12. Defiance, OH — 21 mi23. Adrian, MI — 28 mi34. Bowling Green, OH — 29 mi45. Hillsdale, MI — 39 mi5
  1. near Toledo, OH 18 mi (30 km)
  2. Defiance, OH 21 mi (33 km)
  3. Adrian, MI 28 mi (46 km)
  4. Bowling Green, OH 29 mi (47 km)
  5. Hillsdale, MI 39 mi (62 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: 41.5183, -84.1453.