U.S. Frost Dates by Weather Station

NOAA station USC00231580 · Missouri

Frost Dates for Chillicothe, MO

NOAA weather station Chillicothe 2 S (USC00231580), Missouri · elevation 780 ft (238 m) · hardiness zone 6a*

  • Lower-risk planting dateafter April 30only 1 spring in 10 still has a frost later
  • Typical last frostApril 1550% chance of a frost after it
  • Typical first fall frostOctober 2150% chance of a frost before it
  • Frost-free season187 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Chillicothe, MOSpring: a frost after April 1 in 9 years out of 10, after April 15 in half of the years, after April 30 in 1 year out of 10. Fall: the first frost comes before October 7 in 1 year out of 10, before October 21 in half of the years, before November 1 in 9 years out of 10. Typical frost-free season: 187 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 15First frost ~Oct 21Frost season at Chillicothe, MOSpring: a frost after April 1 in 9 years out of 10, after April 15 in half of the years, after April 30 in 1 year out of 10. Fall: the first frost comes before October 7 in 1 year out of 10, before October 21 in half of the years, before November 1 in 9 years out of 10. Typical frost-free season: 187 days.JFMAMJJASONDLast frost ~Apr 15First frost ~Oct 21
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 26 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)April 30October 7
50% (typical)April 15October 21
90% (likely)April 1November 1
Frost-free season (32°F, 50% chance)
187 days
Hard frost (28°F), last in spring, 50% chance after
April 5
Hard frost (28°F), first in fall, 50% chance before
November 1

The last 15 years (2006–2020 normals)

Typical last frost April 15 (same as the 30-year normal), typical first fall frost October 22 (1 day later). Frost-free season 189 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 Chillicothe: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 30, 20% April 25, 30% April 21, 40% April 18, 50% April 15, 60% April 12, 70% April 9, 80% April 6, 90% April 1. Observed last spring frost in recent years: 2021 April 23, 2022 April 27, 2023 April 24, 2024 April 6, 2025 April 9, 2026 March 29.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1Apr 30Apr 15Apr 12021: April 232022: April 272023: April 242024: April 62025: April 92026: March 29Fall at Chillicothe: chance of a frost before this dateFall, chance of a frost before the date: 10% October 7, 20% October 12, 30% October 15, 40% October 18, 50% October 21, 60% October 23, 70% October 26, 80% October 29, 90% November 1. Observed first fall frost in recent years: 2021 November 2, 2022 October 8, 2023 October 28, 2024 October 16, 2025 October 31.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 7Oct 21Nov 12021: November 22022: October 82023: October 282024: October 162025: October 31
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 2
2022April 27October 8
2023April 24October 28
2024April 6October 16
2025April 9October 31
2026March 29season not over yet

What these dates mean

April 30 is the cautious spring date for Chillicothe; with only a 10 % chance of a light frost later, a gardener can confidently set out tender crops. The early spring date of April 1 carries a 90 % chance of frost later and is a gamble.

The 50 % date in spring is April 15, meaning there is an even chance of a light frost occurring later than that day. In fall the 50 % date is October 21, indicating an even chance of a light frost occurring earlier. The cautious fall date is October 7, where only a 10 % chance of a frost earlier lets a gardener finish harvesting tender crops. Hard-frost dates (28 °F) are April 5 and November 1; a hard frost can injure plants that would survive a 32 °F light frost, making it a greater concern.

How to read the probabilities

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

  • Spring: "10% after April 30" 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 7" 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 Chillicothe, MONumbered nearest stations: 1 — Carrollton, MO — 29 mi; 2 — Spickard, MO — 34 mi; 3 — Bethany, MO — 42 mi; 4 — Amity, MO — 44 mi; 5 — Salisbury, MO — 46 mi.25 mi · 40 km1. Carrollton, MO — 29 mi12. Spickard, MO — 34 mi23. Bethany, MO — 42 mi34. Amity, MO — 44 mi45. Salisbury, MO — 46 mi5
  1. Carrollton, MO 29 mi (46 km)
  2. Spickard, MO 34 mi (55 km)
  3. Bethany, MO 42 mi (68 km)
  4. Amity, MO 44 mi (72 km)
  5. Salisbury, MO 46 mi (73 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: 39.775, -93.5358.