U.S. Frost Dates by Weather Station

NOAA station USC00232809 · Missouri

Frost Dates for Farmington, MO

NOAA weather station Farmington (USC00232809), Missouri · elevation 900 ft (274 m) · hardiness zone 6b*

  • Lower-risk planting dateafter April 30only 1 spring in 10 still has a frost later
  • Typical last frostApril 1350% chance of a frost after it
  • Typical first fall frostOctober 2150% chance of a frost before it
  • Frost-free season191 daystypical year, 32°F
  • Hardiness zone6bcalculated*

The year at a glance

Frost season at Farmington, MOSpring: a frost after March 28 in 9 years out of 10, after April 13 in half of the years, after April 30 in 1 year out of 10. Fall: the first frost comes before October 6 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: 191 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 13First frost ~Oct 21Frost season at Farmington, MOSpring: a frost after March 28 in 9 years out of 10, after April 13 in half of the years, after April 30 in 1 year out of 10. Fall: the first frost comes before October 6 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: 191 days.JFMAMJJASONDLast frost ~Apr 13First 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 27 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)April 30October 6
50% (typical)April 13October 21
90% (likely)March 28November 1
Frost-free season (32°F, 50% chance)
191 days
Hard frost (28°F), last in spring, 50% chance after
April 1
Hard frost (28°F), first in fall, 50% chance before
November 1

The last 15 years (2006–2020 normals)

Typical last frost April 10 (3 days earlier than the 30-year normal), typical first fall frost October 23 (2 days later). Frost-free season 192 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 Farmington: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 30, 20% April 24, 30% April 20, 40% April 17, 50% April 13, 60% April 10, 70% April 6, 80% April 2, 90% March 28.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1Apr 30Apr 13Mar 28Fall at Farmington: chance of a frost before this dateFall, chance of a frost before the date: 10% October 6, 20% October 12, 30% October 16, 40% October 18, 50% October 21, 60% October 23, 70% October 25, 80% October 29, 90% November 1. Observed first fall frost in recent years: 2023 October 30.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 6Oct 21Nov 12023: October 30
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
2021incomplete recordincomplete record
2022incomplete recordincomplete record
2023incomplete recordOctober 30
2024incomplete recordno data
2025no datano data
2026no dataseason not over yet

What these dates mean

The cautious fall date in Farmington for finishing the harvest is October 6, when there is only a 10 % chance that a light frost has arrived.

The 50% light-frost dates are April 13 and October 21; a gardener has an even chance of a frost later than April 13 in spring or earlier than October 21 in fall. The median hard-frost dates are April 1 and November 1, indicating when a 28 °F frost is as likely as not. The record spans 27 years, and the interval between the two 32 °F 50% dates is 191 days.

The cautious spring date for setting out tender crops is April 30, which carries a 10 % chance of a later light frost, while March 28 represents a 90 % chance and is a gamble. A hard frost at 28 °F can damage plants that survive a light frost at 32 °F.

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 6" 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 Farmington, MONumbered nearest stations: 1 — Fredericktown, MO — 16 mi; 2 — Perryville, MO — 27 mi; 3 — Festus, MO — 30 mi; 4 — Jackson, MO — 50 mi; 5 — near Belleville, IL — 59 mi.MOIL25 mi · 40 km1. Fredericktown, MO — 16 mi12. Perryville, MO — 27 mi23. Festus, MO — 30 mi34. Jackson, MO — 50 mi45. near Belleville, IL — 59 mi5
  1. Fredericktown, MO 16 mi (26 km)
  2. Perryville, MO 27 mi (44 km)
  3. Festus, MO 30 mi (49 km)
  4. Jackson, MO 50 mi (80 km)
  5. near Belleville, IL 59 mi (95 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: 37.7919, -90.4097.