U.S. Frost Dates by Weather Station

NOAA station USW00014848 · Indiana

Frost Dates near South Bend, IN

NOAA weather station South Bend Michiana Regional Airport (USW00014848), Indiana · elevation 773 ft (236 m) · hardiness zone 6a*

South Bend is the nearest town to the station (3.8 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 17only 1 spring in 10 still has a frost later
  • Typical last frostMay 150% chance of a frost after it
  • Typical first fall frostOctober 1950% chance of a frost before it
  • Frost-free season170 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season near South Bend, INSpring: a frost after April 16 in 9 years out of 10, after May 1 in half of the years, after May 17 in 1 year out of 10. Fall: the first frost comes before October 5 in 1 year out of 10, before October 19 in half of the years, before November 1 in 9 years out of 10. Typical frost-free season: 170 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 1First frost ~Oct 19Frost season near South Bend, INSpring: a frost after April 16 in 9 years out of 10, after May 1 in half of the years, after May 17 in 1 year out of 10. Fall: the first frost comes before October 5 in 1 year out of 10, before October 19 in half of the years, before November 1 in 9 years out of 10. Typical frost-free season: 170 days.JFMAMJJASONDLast frost ~May 1First frost ~Oct 19
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)May 17October 5
50% (typical)May 1October 19
90% (likely)April 16November 1
Frost-free season (32°F, 50% chance)
170 days
Hard frost (28°F), last in spring, 50% chance after
April 19
Hard frost (28°F), first in fall, 50% chance before
October 31

The last 15 years (2006–2020 normals)

Typical last frost May 1 (same as the 30-year normal), typical first fall frost October 21 (2 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 near South Bend: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 17, 20% May 11, 30% May 7, 40% May 4, 50% May 1, 60% April 28, 70% April 24, 80% April 20, 90% April 16. Observed last spring frost in recent years: 2021 May 13, 2022 April 27, 2023 April 27, 2024 April 25, 2025 April 16, 2026 May 2.Spring: last frostChance of a frost after this date10%50%90%May 1May 17May 1Apr 162021: May 132022: April 272023: April 272024: April 252025: April 162026: May 2Fall near South Bend: chance of a frost before this dateFall, chance of a frost before the date: 10% October 5, 20% October 10, 30% October 14, 40% October 17, 50% October 19, 60% October 21, 70% October 24, 80% October 27, 90% November 1. Observed first fall frost in recent years: 2021 October 27, 2022 October 20, 2023 October 30, 2024 October 27, 2025 October 24.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 5Oct 19Nov 12021: October 272022: October 202023: October 302024: October 272025: 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 13October 27
2022April 27October 20
2023April 27October 30
2024April 25October 27
2025April 16October 24
2026May 2season not over yet

What these dates mean

The 170 days between the 50% dates in the South Bend area mark the span from May 1 to October 19, during which tender crops can grow without an even-odds light frost.

For a gardener, the 50% dates are simply the median points where a 32 °F light frost is equally likely to have occurred before or to occur after; they are not frost dates themselves. The cautious spring date for setting out tender crops is May 17, when there is only a 10 % chance of a later light frost, while planting on April 16 carries a 90 % chance and is a gamble. In the fall, the cautious date to finish harvesting tender crops is October 5, with only a 10 % chance that a light frost has already arrived, whereas counting on crops to survive until November 1 involves a 90 % chance of an earlier frost.

A hard frost at 28 °F, such as those reflected by the April 19 and October 31 median dates, can damage plant tissue more severely than a light frost at 32 °F.

How to read the probabilities

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

  • Spring: "10% after May 17" 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 5" 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 South Bend, INNumbered nearest stations: 1 — Lakeville, IN — 13 mi; 2 — Dowagiac, MI — 21 mi; 3 — Laporte, IN — 22 mi; 4 — Goshen, IN — 25 mi; 5 — Plymouth, IN — 25 mi.MIILOH25 mi · 40 km1. Lakeville, IN — 13 mi12. Dowagiac, MI — 21 mi23. Laporte, IN — 22 mi34. Goshen, IN — 25 mi45. Plymouth, IN — 25 mi5
  1. Lakeville, IN 13 mi (20 km)
  2. Dowagiac, MI 21 mi (35 km)
  3. Laporte, IN 22 mi (36 km)
  4. Goshen, IN 25 mi (40 km)
  5. Plymouth, IN 25 mi (41 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: 41.7072, -86.3164.