U.S. Frost Dates by Weather Station

NOAA station USC00123082 · Indiana

Frost Dates near Frankfort, IN

NOAA weather station Frankfort Disposal (USC00123082), Indiana · elevation 824 ft (251 m) · hardiness zone 6a*

Frankfort is the nearest town to the station (1.4 mi away) in GeoNames (CC BY 4.0). The dates below are measured at the station, not in the town itself.

  • Lower-risk planting dateafter May 7only 1 spring in 10 still has a frost later
  • Typical last frostApril 2150% chance of a frost after it
  • Typical first fall frostOctober 2150% chance of a frost before it
  • Frost-free season181 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season near Frankfort, INSpring: a frost after April 7 in 9 years out of 10, after April 21 in half of the years, after May 7 in 1 year out of 10. Fall: the first frost comes before October 6 in 1 year out of 10, before October 21 in half of the years, before November 1 in 9 years out of 10. Typical frost-free season: 181 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 21First frost ~Oct 21Frost season near Frankfort, INSpring: a frost after April 7 in 9 years out of 10, after April 21 in half of the years, after May 7 in 1 year out of 10. Fall: the first frost comes before October 6 in 1 year out of 10, before October 21 in half of the years, before November 1 in 9 years out of 10. Typical frost-free season: 181 days.JFMAMJJASONDLast frost ~Apr 21First frost ~Oct 21
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 29 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 7October 6
50% (typical)April 21October 21
90% (likely)April 7November 1
Frost-free season (32°F, 50% chance)
181 days
Hard frost (28°F), last in spring, 50% chance after
April 7
Hard frost (28°F), first in fall, 50% chance before
November 1

The last 15 years (2006–2020 normals)

Typical last frost April 21 (same as the 30-year normal), typical first fall frost October 23 (2 days later). Frost-free season 184 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 near Frankfort: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 7, 20% May 1, 30% April 28, 40% April 24, 50% April 21, 60% April 19, 70% April 16, 80% April 12, 90% April 7. Observed last spring frost in recent years: 2021 April 21, 2024 April 6.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 7Apr 21Apr 72021: April 212024: April 6Fall near Frankfort: chance of a frost before this dateFall, chance of a frost before the date: 10% October 6, 20% October 12, 30% October 15, 40% October 18, 50% October 21, 60% October 23, 70% October 26, 80% October 29, 90% November 1. Observed first fall frost in recent years: 2021 November 2, 2023 October 31, 2024 October 17, 2025 October 24.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 6Oct 21Nov 12021: November 22023: October 312024: 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
2021April 21November 2
2022incomplete recordincomplete record
2023incomplete recordOctober 31
2024April 6October 17
2025incomplete recordOctober 24
2026incomplete recordseason not over yet

What these dates mean

The cautious fall date for finishing the harvest in the Frankfort area is October 6, when there is only a 10 % chance a light frost has arrived.

For light frosts, the 50 % dates are April 21 and October 21. On April 21 there is a 50 % chance of a frost later than this date, while on October 21 there is a 50 % chance of a frost earlier than this date. Gardeners who prefer a lower risk in spring use the cautious date of May 7, which carries a 10 % chance of a frost later, whereas the early spring date of April 7 carries a 90 % chance and is a gamble.

Hard frosts are recorded with a 28 °F threshold; the 50 % hard-frost dates are April 7 and November 1. Because a hard frost can damage plant tissue more severely than a light frost, it is a more critical consideration for tender crops.

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 6" 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 Frankfort, INNumbered nearest stations: 1 — Kokomo, IN — 21 mi; 2 — Lafayette, IN — 21 mi; 3 — Tipton, IN — 22 mi; 4 — Whitestown, IN — 22 mi; 5 — Lafayette (Purdue University Airport), IN — 24 mi.IL25 mi · 40 km1. Kokomo, IN — 21 mi12. Lafayette, IN — 21 mi23. Tipton, IN — 22 mi34. Whitestown, IN — 22 mi45. Lafayette (Purdue University Airport), IN — 24 mi5
  1. Kokomo, IN 21 mi (33 km)
  2. Lafayette, IN 21 mi (34 km)
  3. Tipton, IN 22 mi (35 km)
  4. Whitestown, IN 22 mi (36 km)
  5. Lafayette (Purdue University Airport), IN 24 mi (39 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: 40.2986, -86.5067.