U.S. Frost Dates by Weather Station

NOAA station USC00120676 · Indiana

Frost Dates for Berne, IN

NOAA weather station Berne WWTP (USC00120676), Indiana · elevation 839 ft (256 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 7only 1 spring in 10 still has a frost later
  • Typical last frostApril 2350% chance of a frost after it
  • Typical first fall frostOctober 2250% chance of a frost before it
  • Frost-free season181 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Berne, INSpring: a frost after April 9 in 9 years out of 10, after April 23 in half of the years, after May 7 in 1 year out of 10. Fall: the first frost comes before October 9 in 1 year out of 10, before October 22 in half of the years, before November 4 in 9 years out of 10. Typical frost-free season: 181 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 23First frost ~Oct 22Frost season at Berne, INSpring: a frost after April 9 in 9 years out of 10, after April 23 in half of the years, after May 7 in 1 year out of 10. Fall: the first frost comes before October 9 in 1 year out of 10, before October 22 in half of the years, before November 4 in 9 years out of 10. Typical frost-free season: 181 days.JFMAMJJASONDLast frost ~Apr 23First frost ~Oct 22
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 7October 9
50% (typical)April 23October 22
90% (likely)April 9November 4
Frost-free season (32°F, 50% chance)
181 days
Hard frost (28°F), last in spring, 50% chance after
April 13
Hard frost (28°F), first in fall, 50% chance before
November 2

The last 15 years (2006–2020 normals)

Typical last frost April 20 (3 days earlier than the 30-year normal), typical first fall frost October 27 (5 days later). Frost-free season 188 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 Berne: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 7, 20% May 2, 30% April 30, 40% April 27, 50% April 23, 60% April 21, 70% April 18, 80% April 15, 90% April 9. Observed last spring frost in recent years: 2021 May 1, 2022 April 28, 2023 April 26, 2024 April 7, 2025 April 17, 2026 May 3.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 7Apr 23Apr 92021: May 12022: April 282023: April 262024: April 72025: April 172026: May 3Fall at Berne: chance of a frost before this dateFall, chance of a frost before the date: 10% October 9, 20% October 14, 30% October 17, 40% October 20, 50% October 22, 60% October 25, 70% October 29, 80% October 31, 90% November 4. Observed first fall frost in recent years: 2021 November 3, 2022 October 8, 2023 October 23, 2024 October 17, 2025 October 24.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 9Oct 22Nov 42021: November 32022: October 82023: October 232024: October 172025: October 24
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 1November 3
2022April 28October 8
2023April 26October 23
2024April 7October 17
2025April 17October 24
2026May 3season not over yet

What these dates mean

Setting out tender crops on the early spring date of April 9 carries a 90% chance of a frost later in Berne, making it a gamble for growers. The cautious spring date is May 7, when only a 10% chance of frost remains, while the median 50% date of April 23 marks the point at which a frost is equally likely either side. A cautious plan would use May 7 for spring planting and October 9 for fall harvest.

In the fall, the cautious date to finish harvesting tender crops is October 9, with only a 10% chance that a frost has already arrived; the 50% fall date of October 22 indicates even odds for a frost earlier. The 50% hard-frost dates—April 13 in spring and November 2 in fall—show when a 28°F frost is as likely as not, and a hard frost can damage plants more severely than a light frost because it occurs at a lower 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 7" 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 9" 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 Berne, INNumbered nearest stations: 1 — Bluffton, IN — 15 mi; 2 — Celina, OH — 22 mi; 3 — Hartford City, IN — 25 mi; 4 — Fort Wayne, IN — 25 mi; 5 — Farmland, IN — 31 mi.INOH25 mi · 40 km1. Bluffton, IN — 15 mi12. Celina, OH — 22 mi23. Hartford City, IN — 25 mi34. Fort Wayne, IN — 25 mi45. Farmland, IN — 31 mi5
  1. Bluffton, IN 15 mi (25 km)
  2. Celina, OH 22 mi (35 km)
  3. Hartford City, IN 25 mi (40 km)
  4. Fort Wayne, IN 25 mi (41 km)
  5. Farmland, IN 31 mi (50 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: 40.6683, -84.93.