U.S. Frost Dates by Weather Station

NOAA station USC00237300 · Missouri

Frost Dates for Rosebud, MO

NOAA weather station Rosebud (USC00237300), Missouri · elevation 730 ft (223 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 12only 1 spring in 10 still has a frost later
  • Typical last frostApril 2750% chance of a frost after it
  • Typical first fall frostOctober 1350% chance of a frost before it
  • Frost-free season168 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Rosebud, MOSpring: a frost after April 11 in 9 years out of 10, after April 27 in half of the years, after May 12 in 1 year out of 10. Fall: the first frost comes before September 29 in 1 year out of 10, before October 13 in half of the years, before October 26 in 9 years out of 10. Typical frost-free season: 168 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 27First frost ~Oct 13Frost season at Rosebud, MOSpring: a frost after April 11 in 9 years out of 10, after April 27 in half of the years, after May 12 in 1 year out of 10. Fall: the first frost comes before September 29 in 1 year out of 10, before October 13 in half of the years, before October 26 in 9 years out of 10. Typical frost-free season: 168 days.JFMAMJJASONDLast frost ~Apr 27First frost ~Oct 13
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)May 12September 29
50% (typical)April 27October 13
90% (likely)April 11October 26
Frost-free season (32°F, 50% chance)
168 days
Hard frost (28°F), last in spring, 50% chance after
April 14
Hard frost (28°F), first in fall, 50% chance before
October 24

The last 15 years (2006–2020 normals)

Typical last frost April 28 (1 day later than the 30-year normal), typical first fall frost October 16 (3 days later). Frost-free season 172 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 Rosebud: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 12, 20% May 7, 30% May 3, 40% April 30, 50% April 27, 60% April 24, 70% April 20, 80% April 16, 90% April 11. Observed last spring frost in recent years: 2021 May 14, 2022 April 27, 2023 May 5, 2025 April 16, 2026 April 19.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 12Apr 27Apr 112021: May 142022: April 272023: May 52025: April 162026: April 19Fall at Rosebud: chance of a frost before this dateFall, chance of a frost before the date: 10% September 29, 20% October 3, 30% October 7, 40% October 10, 50% October 13, 60% October 15, 70% October 18, 80% October 21, 90% October 26. Observed first fall frost in recent years: 2021 November 1, 2022 October 8, 2023 October 30, 2024 October 16, 2025 October 23.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 29Oct 13Oct 262021: November 12022: October 82023: October 302024: October 162025: October 23
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 14November 1
2022April 27October 8
2023May 5October 30
2024incomplete recordOctober 16
2025April 16October 23
2026April 19season not over yet

What these dates mean

May 12 is the cautious spring date for Rosebud, with a 10 % chance of a light frost later than that day, and it lets a gardener set out tender crops with minimal frost risk.

The 50 % dates—April 27 in spring and October 13 in fall—indicate the point where a light frost is equally likely to occur before or after, offering a neutral reference for timing decisions. The median hard-frost dates are April 14 and October 24; these are the days when a 28 °F frost is as likely as not. September 29 is the cautious fall date, with only a 10 % chance that a light frost has arrived earlier, so it marks the latest time to finish harvesting tender crops. By contrast, April 11 and October 26 carry a 90 % chance of frost, making them risky choices for tender crops.

A hard frost at 28 °F can damage plant tissue that typically survives 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 May 12" 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 Rosebud, MONumbered nearest stations: 1 — Freedom, MO — 18 mi; 2 — Vichy Rolla National Airport, MO — 31 mi; 3 — near Rolla, MO — 40 mi; 4 — near Weldon Spring, MO — 41 mi; 5 — St. Louis (Spirit of St. Louis Airport), MO — 41 mi.MOIL25 mi · 40 km1. Freedom, MO — 18 mi12. Vichy Rolla National Airport, MO — 31 mi23. near Rolla, MO — 40 mi34. near Weldon Spring, MO — 41 mi45. St. Louis (Spirit of St. Louis Airport), MO — 41 mi5
  1. Freedom, MO 18 mi (29 km)
  2. Vichy Rolla National Airport, MO 31 mi (49 km)
  3. near Rolla, MO 40 mi (65 km)
  4. near Weldon Spring, MO 41 mi (66 km)
  5. St. Louis (Spirit of St. Louis Airport), MO 41 mi (67 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: 38.4508, -91.3753.