U.S. Frost Dates by Weather Station

NOAA station USC00233038 · Missouri

Frost Dates for Fredericktown, MO

NOAA weather station Fredericktown (USC00233038), Missouri · elevation 760 ft (232 m) · hardiness zone 6b*

  • Lower-risk planting dateafter May 8only 1 spring in 10 still has a frost later
  • Typical last frostApril 2150% chance of a frost after it
  • Typical first fall frostOctober 1650% chance of a frost before it
  • Frost-free season174 daystypical year, 32°F
  • Hardiness zone6bcalculated*

The year at a glance

Frost season at Fredericktown, MOSpring: a frost after April 8 in 9 years out of 10, after April 21 in half of the years, after May 8 in 1 year out of 10. Fall: the first frost comes before October 1 in 1 year out of 10, before October 16 in half of the years, before October 28 in 9 years out of 10. Typical frost-free season: 174 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 21First frost ~Oct 16Frost season at Fredericktown, MOSpring: a frost after April 8 in 9 years out of 10, after April 21 in half of the years, after May 8 in 1 year out of 10. Fall: the first frost comes before October 1 in 1 year out of 10, before October 16 in half of the years, before October 28 in 9 years out of 10. Typical frost-free season: 174 days.JFMAMJJASONDLast frost ~Apr 21First frost ~Oct 16
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 8October 1
50% (typical)April 21October 16
90% (likely)April 8October 28
Frost-free season (32°F, 50% chance)
174 days
Hard frost (28°F), last in spring, 50% chance after
April 10
Hard frost (28°F), first in fall, 50% chance before
October 26

The last 15 years (2006–2020 normals)

Typical last frost April 21 (same as the 30-year normal), typical first fall frost October 18 (2 days later). Frost-free season 180 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 Fredericktown: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 8, 20% May 3, 30% April 29, 40% April 25, 50% April 21, 60% April 18, 70% April 15, 80% April 12, 90% April 8. Observed last spring frost in recent years: 2022 April 19.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 8Apr 21Apr 82022: April 19Fall at Fredericktown: chance of a frost before this dateFall, chance of a frost before the date: 10% October 1, 20% October 6, 30% October 10, 40% October 13, 50% October 16, 60% October 18, 70% October 20, 80% October 24, 90% October 28. Observed first fall frost in recent years: 2021 October 20.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 1Oct 16Oct 282021: October 20
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 recordOctober 20
2022April 19no data
2023no datano data
2024no datano data
2025no datano data
2026no dataseason not over yet

What these dates mean

October 1 marks the cautious fall date in Fredericktown for finishing the harvest; there is only a 10 % chance that a light frost has arrived before that day, making it the point at which tender crops can be pulled in with minimal risk. In spring the cautious date for setting out tender crops is May 8, when the chance of a light frost later than that date is only 10 %.

The 50 % dates—April 21 for spring and October 16 for fall—are the moments when the odds of a light frost later (or earlier) are even. The median hard-frost dates are April 10 in spring and October 26 in fall, indicating when a 50 % chance of a 28 °F event exists.

Hard frost at 28 °F matters more than a light frost at 32 °F because it can damage plants that would survive the milder temperature.

How to read the probabilities

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

  • Spring: "10% after May 8" 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 1" 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 Fredericktown, MONumbered nearest stations: 1 — Farmington, MO — 16 mi; 2 — Perryville, MO — 24 mi; 3 — Jackson, MO — 38 mi; 4 — Festus, MO — 46 mi; 5 — Cape Girardeau, MO — 47 mi.MOILKY25 mi · 40 km1. Farmington, MO — 16 mi12. Perryville, MO — 24 mi23. Jackson, MO — 38 mi34. Festus, MO — 46 mi45. Cape Girardeau, MO — 47 mi5
  1. Farmington, MO 16 mi (26 km)
  2. Perryville, MO 24 mi (38 km)
  3. Jackson, MO 38 mi (61 km)
  4. Festus, MO 46 mi (74 km)
  5. Cape Girardeau, MO 47 mi (76 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: 37.5742, -90.3075.