U.S. Frost Dates by Weather Station

NOAA station USC00237506 · Missouri

Frost Dates for Salem, MO

NOAA weather station Salem (USC00237506), Missouri · elevation 1205 ft (367 m) · hardiness zone 6b*

  • Lower-risk planting dateafter May 5only 1 spring in 10 still has a frost later
  • Typical last frostApril 1750% chance of a frost after it
  • Typical first fall frostOctober 1850% chance of a frost before it
  • Frost-free season182 daystypical year, 32°F
  • Hardiness zone6bcalculated*

The year at a glance

Frost season at Salem, MOSpring: a frost after March 31 in 9 years out of 10, after April 17 in half of the years, after May 5 in 1 year out of 10. Fall: the first frost comes before October 3 in 1 year out of 10, before October 18 in half of the years, before October 31 in 9 years out of 10. Typical frost-free season: 182 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 17First frost ~Oct 18Frost season at Salem, MOSpring: a frost after March 31 in 9 years out of 10, after April 17 in half of the years, after May 5 in 1 year out of 10. Fall: the first frost comes before October 3 in 1 year out of 10, before October 18 in half of the years, before October 31 in 9 years out of 10. Typical frost-free season: 182 days.JFMAMJJASONDLast frost ~Apr 17First frost ~Oct 18
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 5October 3
50% (typical)April 17October 18
90% (likely)March 31October 31
Frost-free season (32°F, 50% chance)
182 days
Hard frost (28°F), last in spring, 50% chance after
April 3
Hard frost (28°F), first in fall, 50% chance before
October 30

The last 15 years (2006–2020 normals)

Typical last frost April 16 (1 day earlier than the 30-year normal), typical first fall frost October 21 (3 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 Salem: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 5, 20% April 29, 30% April 24, 40% April 20, 50% April 17, 60% April 13, 70% April 9, 80% April 5, 90% March 31. Observed last spring frost in recent years: 2022 April 19, 2023 April 24, 2024 April 22, 2025 April 9, 2026 March 18.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 5Apr 17Mar 312022: April 192023: April 242024: April 222025: April 92026: March 18Fall at Salem: chance of a frost before this dateFall, chance of a frost before the date: 10% October 3, 20% October 9, 30% October 12, 40% October 15, 50% October 18, 60% October 21, 70% October 24, 80% October 28, 90% October 31. Observed first fall frost in recent years: 2022 October 18, 2023 October 30, 2025 November 10.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 3Oct 18Oct 312022: October 182023: October 302025: November 10
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
2022April 19October 18
2023April 24October 30
2024April 22incomplete record
2025April 9November 10
2026March 18season not over yet

What these dates mean

Planting tender crops on the early spring date of March 31 in Salem carries a 90% chance of a light frost occurring later, making it a high-risk gamble. The cautious alternative for starting tender varieties is the later date of May 5, when only a 10% chance of a light frost remains. For the fall season, the low-risk date to finish harvesting tender crops is October 3, which has a 10% chance of a light frost already having arrived, whereas aiming for October 31 would gamble with a 90% chance of frost.

The 50% dates—April 17 for spring and October 18 for fall—represent the median point where the probability of a light frost is even; they are not frost dates but indicate when the chance of frost switches from more likely to less likely. The hard-frost median dates are April 3 in spring and October 30 in fall, and a hard frost at 28 °F can damage vegetation more severely than a light frost at 32 °F, so gardeners should be aware of both thresholds.

How to read the probabilities

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

  • Spring: "10% after May 5" 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 3" 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 Salem, MONumbered nearest stations: 1 — Licking, MO — 20 mi; 2 — near Rolla, MO — 26 mi; 3 — Vichy Rolla National Airport, MO — 37 mi; 4 — Waynesville, MO — 40 mi; 5 — Mountain Grove, MO — 52 mi.25 mi · 40 km1. Licking, MO — 20 mi12. near Rolla, MO — 26 mi23. Vichy Rolla National Airport, MO — 37 mi34. Waynesville, MO — 40 mi45. Mountain Grove, MO — 52 mi5
  1. Licking, MO 20 mi (32 km)
  2. near Rolla, MO 26 mi (42 km)
  3. Vichy Rolla National Airport, MO 37 mi (59 km)
  4. Waynesville, MO 40 mi (64 km)
  5. Mountain Grove, MO 52 mi (83 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: 37.6339, -91.5361.