U.S. Frost Dates by Weather Station

NOAA station USC00238051 · Missouri

Frost Dates for Steffenville, MO

NOAA weather station Steffenville (USC00238051), Missouri · elevation 705 ft (215 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 4only 1 spring in 10 still has a frost later
  • Typical last frostApril 1750% chance of a frost after it
  • Typical first fall frostOctober 1950% chance of a frost before it
  • Frost-free season184 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Steffenville, MOSpring: a frost after April 3 in 9 years out of 10, after April 17 in half of the years, after May 4 in 1 year out of 10. Fall: the first frost comes before September 30 in 1 year out of 10, before October 19 in half of the years, before October 31 in 9 years out of 10. Typical frost-free season: 184 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 17First frost ~Oct 19Frost season at Steffenville, MOSpring: a frost after April 3 in 9 years out of 10, after April 17 in half of the years, after May 4 in 1 year out of 10. Fall: the first frost comes before September 30 in 1 year out of 10, before October 19 in half of the years, before October 31 in 9 years out of 10. Typical frost-free season: 184 days.JFMAMJJASONDLast frost ~Apr 17First frost ~Oct 19
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 4September 30
50% (typical)April 17October 19
90% (likely)April 3October 31
Frost-free season (32°F, 50% chance)
184 days
Hard frost (28°F), last in spring, 50% chance after
April 7
Hard frost (28°F), first in fall, 50% chance before
October 30

The last 15 years (2006–2020 normals)

Typical last frost April 17 (same as the 30-year normal), typical first fall frost October 21 (2 days later). Frost-free season 186 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 Steffenville: 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 17, 60% April 15, 70% April 12, 80% April 9, 90% April 3. 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 1May 4Apr 17Apr 32021: April 232022: April 272023: April 242024: April 62025: April 92026: March 29Fall at Steffenville: chance of a frost before this dateFall, chance of a frost before the date: 10% September 30, 20% October 6, 30% October 12, 40% October 15, 50% October 19, 60% October 21, 70% October 24, 80% October 27, 90% October 31. Observed first fall frost in recent years: 2021 November 2, 2022 October 8, 2023 October 30, 2024 October 16, 2025 November 2.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 30Oct 19Oct 312021: November 22022: October 82023: October 302024: October 162025: November 2
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 30
2024April 6October 16
2025April 9November 2
2026March 29season not over yet

What these dates mean

The 184 days between the 32°F 50% dates of April 17 and October 19 in Steffenville span the interval when light frosts are less likely, providing the window for most garden activities. Light-frost risk is balanced at those median dates, while the record covers 28 years.

In spring, the cautious date for setting out tender crops is May 4, which carries only a 10% chance of a frost later than that day; planting on April 3 involves a 90% chance and is a gamble. In fall, the cautious date to finish harvesting tender crops is September 30, with a 10% chance of a frost earlier than that day, while October 31 represents a 90% gamble. The 50% dates of April 17 and October 19 are not frost dates but mark even odds.

Hard frosts at 28°F are more damaging than light frosts at 32°F, so the 50% hard-frost dates of April 7 and October 30 indicate when severe freezing becomes as likely as not.

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 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 Steffenville, MONumbered nearest stations: 1 — Shelbina, MO — 22 mi; 2 — near Canton, MO — 23 mi; 3 — Quincy Dam 21, IL — 25 mi; 4 — Hannibal, MO — 32 mi; 5 — near Macon, MO — 36 mi.MOIL25 mi · 40 km1. Shelbina, MO — 22 mi12. near Canton, MO — 23 mi23. Quincy Dam 21, IL — 25 mi34. Hannibal, MO — 32 mi45. near Macon, MO — 36 mi5
  1. Shelbina, MO 22 mi (35 km)
  2. near Canton, MO 23 mi (37 km)
  3. Quincy Dam 21, IL 25 mi (40 km)
  4. Hannibal, MO 32 mi (52 km)
  5. near Macon, MO 36 mi (58 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: 39.9703, -91.8875.