U.S. Frost Dates by Weather Station

NOAA station USC00121747 · Indiana

Frost Dates for Columbus, IN

NOAA weather station Columbus (USC00121747), Indiana · elevation 609 ft (186 m) · hardiness zone 6b*

  • Lower-risk planting dateafter April 30only 1 spring in 10 still has a frost later
  • Typical last frostApril 1150% chance of a frost after it
  • Typical first fall frostOctober 2550% chance of a frost before it
  • Frost-free season195 daystypical year, 32°F
  • Hardiness zone6bcalculated*

The year at a glance

Frost season at Columbus, INSpring: a frost after March 31 in 9 years out of 10, after April 11 in half of the years, after April 30 in 1 year out of 10. Fall: the first frost comes before October 12 in 1 year out of 10, before October 25 in half of the years, before November 7 in 9 years out of 10. Typical frost-free season: 195 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 11First frost ~Oct 25Frost season at Columbus, INSpring: a frost after March 31 in 9 years out of 10, after April 11 in half of the years, after April 30 in 1 year out of 10. Fall: the first frost comes before October 12 in 1 year out of 10, before October 25 in half of the years, before November 7 in 9 years out of 10. Typical frost-free season: 195 days.JFMAMJJASONDLast frost ~Apr 11First frost ~Oct 25
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 30 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)April 30October 12
50% (typical)April 11October 25
90% (likely)March 31November 7
Frost-free season (32°F, 50% chance)
195 days
Hard frost (28°F), last in spring, 50% chance after
April 1
Hard frost (28°F), first in fall, 50% chance before
November 5

The last 15 years (2006–2020 normals)

Typical last frost April 13 (2 days later than the 30-year normal), typical first fall frost October 28 (3 days later). Frost-free season 197 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 Columbus: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 30, 20% April 23, 30% April 18, 40% April 15, 50% April 11, 60% April 8, 70% April 6, 80% April 3, 90% March 31. Observed last spring frost in recent years: 2021 April 22, 2024 April 7, 2026 March 30.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1Apr 30Apr 11Mar 312021: April 222024: April 72026: March 30Fall at Columbus: chance of a frost before this dateFall, chance of a frost before the date: 10% October 12, 20% October 17, 30% October 21, 40% October 23, 50% October 25, 60% October 28, 70% October 30, 80% November 1, 90% November 7. Observed first fall frost in recent years: 2021 November 3, 2024 October 17.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 12Oct 25Nov 72021: November 32024: October 17
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 22November 3
2022incomplete recordincomplete record
2023incomplete recordincomplete record
2024April 7October 17
2025incomplete recordincomplete record
2026March 30season not over yet

What these dates mean

Setting out tender crops on March 31 in Columbus is a gamble, because there is a 90 % chance of a light frost after that date. Waiting until April 30 drops the risk dramatically, leaving only a 10 % chance that a frost will still occur.

The 50 % dates mark the point at which frost is as likely as not. For a light frost the median spring date is April 11, meaning a gardener faces an even chance of a frost later than that day, while the median fall date is October 25, indicating an even chance of a frost earlier. The hard-frost 50 % dates are April 1 in spring and November 5 in fall; a hard frost at 28 °F can injure or kill plants that survive a light frost at 32 °F, so it is a more critical threshold.

A cautious plan therefore uses April 30 to start tender crops and October 12 to finish harvesting them, keeping the probability of a damaging frost low in both seasons.

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 12" 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 Columbus, INNumbered nearest stations: 1 — Shelbyville, IN — 26 mi; 2 — Greensburg, IN — 26 mi; 3 — near Bloomington, IN — 32 mi; 4 — Martinsville, IN — 33 mi; 5 — near Oolitic, IN — 39 mi.INKYOH25 mi · 40 km1. Shelbyville, IN — 26 mi12. Greensburg, IN — 26 mi23. near Bloomington, IN — 32 mi34. Martinsville, IN — 33 mi45. near Oolitic, IN — 39 mi5
  1. Shelbyville, IN 26 mi (42 km)
  2. Greensburg, IN 26 mi (42 km)
  3. near Bloomington, IN 32 mi (52 km)
  4. Martinsville, IN 33 mi (53 km)
  5. near Oolitic, IN 39 mi (63 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: 39.1661, -85.9228.