U.S. Frost Dates by Weather Station

NOAA station USC00129222 · Indiana

Frost Dates for Wanatah, IN

NOAA weather station Wanatah 2 WNW (USC00129222), Indiana · elevation 735 ft (224 m) · hardiness zone 5b*

  • Lower-risk planting dateafter May 14only 1 spring in 10 still has a frost later
  • Typical last frostApril 2950% chance of a frost after it
  • Typical first fall frostOctober 1350% chance of a frost before it
  • Frost-free season166 daystypical year, 32°F
  • Hardiness zone5bcalculated*

The year at a glance

Frost season at Wanatah, INSpring: a frost after April 15 in 9 years out of 10, after April 29 in half of the years, after May 14 in 1 year out of 10. Fall: the first frost comes before October 1 in 1 year out of 10, before October 13 in half of the years, before October 27 in 9 years out of 10. Typical frost-free season: 166 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 29First frost ~Oct 13Frost season at Wanatah, INSpring: a frost after April 15 in 9 years out of 10, after April 29 in half of the years, after May 14 in 1 year out of 10. Fall: the first frost comes before October 1 in 1 year out of 10, before October 13 in half of the years, before October 27 in 9 years out of 10. Typical frost-free season: 166 days.JFMAMJJASONDLast frost ~Apr 29First frost ~Oct 13
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 14October 1
50% (typical)April 29October 13
90% (likely)April 15October 27
Frost-free season (32°F, 50% chance)
166 days
Hard frost (28°F), last in spring, 50% chance after
April 17
Hard frost (28°F), first in fall, 50% chance before
October 25

The last 15 years (2006–2020 normals)

Typical last frost April 28 (1 day earlier than the 30-year normal), typical first fall frost October 17 (4 days later). Frost-free season 172 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 Wanatah: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 14, 20% May 9, 30% May 5, 40% May 1, 50% April 29, 60% April 26, 70% April 23, 80% April 19, 90% April 15. Observed last spring frost in recent years: 2021 May 13, 2022 April 27, 2023 April 27, 2024 April 25, 2025 April 27, 2026 May 4.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 14Apr 29Apr 152021: May 132022: April 272023: April 272024: April 252025: April 272026: May 4Fall at Wanatah: chance of a frost before this dateFall, chance of a frost before the date: 10% October 1, 20% October 5, 30% October 8, 40% October 10, 50% October 13, 60% October 16, 70% October 19, 80% October 23, 90% October 27. Observed first fall frost in recent years: 2021 October 27, 2022 September 29, 2023 October 31, 2024 October 17, 2025 October 27.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 1Oct 13Oct 272021: October 272022: September 292023: October 312024: October 172025: October 27
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 13October 27
2022April 27September 29
2023April 27October 31
2024April 25October 17
2025April 27October 27
2026May 4season not over yet

What these dates mean

May 14, with a 10 % chance of a light frost later, is the cautious spring date that lets a gardener schedule the first planting of tender crops. By waiting until this date the risk of a damaging frost is low, while planting earlier would involve a 90 % chance of frost. In fall, October 1, also a 10 % chance but of a frost earlier, marks the cautious deadline for finishing harvest of tender crops; planting later would face a 90 % chance of frost.

The median light-frost dates, April 29 in spring and October 13 in fall, represent the 50 % chance point; a gardener knows that frost is equally likely to occur on either side of each of those dates. The 50 % hard-frost dates are April 17 and October 25, and a hard frost at 28 °F can damage plants more severely than a light frost at 32 °F because it reaches a lower temperature. The record spans 27 years, and the interval between the two 32 °F 50 % dates is 166 days.

How to read the probabilities

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

  • Spring: "10% after May 14" 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 Wanatah, INNumbered nearest stations: 1 — Indiana Dunes NL, IN — 15 mi; 2 — Laporte, IN — 16 mi; 3 — Lowell, IN — 28 mi; 4 — Plymouth, IN — 32 mi; 5 — Winamac, IN — 34 mi.INILMI25 mi · 40 km1. Indiana Dunes NL, IN — 15 mi12. Laporte, IN — 16 mi23. Lowell, IN — 28 mi34. Plymouth, IN — 32 mi45. Winamac, IN — 34 mi5
  1. Indiana Dunes NL, IN 15 mi (25 km)
  2. Laporte, IN 16 mi (25 km)
  3. Lowell, IN 28 mi (45 km)
  4. Plymouth, IN 32 mi (51 km)
  5. Winamac, IN 34 mi (55 km)

Sources

* Hardiness zone 5b: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 41.4439, -86.9294.