U.S. Frost Dates by Weather Station

NOAA station USC00120177 · Indiana

Frost Dates for Anderson, IN

NOAA weather station Anderson Sewage Plant (USC00120177), Indiana · elevation 841 ft (256 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 5only 1 spring in 10 still has a frost later
  • Typical last frostApril 1950% chance of a frost after it
  • Typical first fall frostOctober 2350% chance of a frost before it
  • Frost-free season186 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Anderson, INSpring: a frost after April 3 in 9 years out of 10, after April 19 in half of the years, after May 5 in 1 year out of 10. Fall: the first frost comes before October 7 in 1 year out of 10, before October 23 in half of the years, before November 6 in 9 years out of 10. Typical frost-free season: 186 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 19First frost ~Oct 23Frost season at Anderson, INSpring: a frost after April 3 in 9 years out of 10, after April 19 in half of the years, after May 5 in 1 year out of 10. Fall: the first frost comes before October 7 in 1 year out of 10, before October 23 in half of the years, before November 6 in 9 years out of 10. Typical frost-free season: 186 days.JFMAMJJASONDLast frost ~Apr 19First frost ~Oct 23
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 5October 7
50% (typical)April 19October 23
90% (likely)April 3November 6
Frost-free season (32°F, 50% chance)
186 days
Hard frost (28°F), last in spring, 50% chance after
April 5
Hard frost (28°F), first in fall, 50% chance before
November 3

The last 15 years (2006–2020 normals)

Typical last frost April 19 (same as the 30-year normal), typical first fall frost October 26 (3 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 Anderson: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 5, 20% April 30, 30% April 25, 40% April 22, 50% April 19, 60% April 16, 70% April 12, 80% April 8, 90% April 3. Observed last spring frost in recent years: 2024 April 22, 2025 April 17, 2026 May 3.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 5Apr 19Apr 32024: April 222025: April 172026: May 3Fall at Anderson: chance of a frost before this dateFall, chance of a frost before the date: 10% October 7, 20% October 13, 30% October 18, 40% October 21, 50% October 23, 60% October 26, 70% October 29, 80% November 1, 90% November 6. Observed first fall frost in recent years: 2024 October 17, 2025 October 24.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 7Oct 23Nov 62024: 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
2021incomplete recordno data
2022no datano data
2023no dataincomplete record
2024April 22October 17
2025April 17October 24
2026May 3season not over yet

What these dates mean

Planting tender crops on April 3 in Anderson is a gamble, because there is a 90 % chance of a light frost later than that date.

The median chance of a light frost in spring occurs on April 19, and the median chance in fall occurs on October 23; these 50 % dates mark the point where frost is equally likely to have arrived or not. A cautious schedule uses the 10 % chance dates – May 5 for setting out tender crops in spring and October 7 for finishing their harvest in fall – while the 90 % chance dates (April 3 and November 6) represent high-risk choices.

A hard frost at 28 °F can damage plants that survive a light frost at 32 °F, so it is a more critical threshold, and the 50 % hard-frost dates are April 5 in spring and November 3 in fall.

How to read the probabilities

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

  • Spring: "10% after May 5" 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 7" 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 Anderson, INNumbered nearest stations: 1 — Tipton, IN — 22 mi; 2 — New Castle, IN — 23 mi; 3 — Farmland, IN — 32 mi; 4 — Hartford City, IN — 32 mi; 5 — Marion, IN — 32 mi.OH25 mi · 40 km1. Tipton, IN — 22 mi12. New Castle, IN — 23 mi23. Farmland, IN — 32 mi34. Hartford City, IN — 32 mi45. Marion, IN — 32 mi5
  1. Tipton, IN 22 mi (36 km)
  2. New Castle, IN 23 mi (37 km)
  3. Farmland, IN 32 mi (51 km)
  4. Hartford City, IN 32 mi (51 km)
  5. Marion, IN 32 mi (52 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: 40.1117, -85.7164.