U.S. Frost Dates by Weather Station

NOAA station USW00014920 · Wisconsin

Frost Dates for La Crosse, WI

NOAA weather station La Crosse Municipal Airport (USW00014920), Wisconsin · elevation 652 ft (199 m) · hardiness zone 5a*

  • Lower-risk planting dateafter May 6only 1 spring in 10 still has a frost later
  • Typical last frostApril 2350% chance of a frost after it
  • Typical first fall frostOctober 1750% chance of a frost before it
  • Frost-free season177 daystypical year, 32°F
  • Hardiness zone5acalculated*

The year at a glance

Frost season at La Crosse, WISpring: a frost after April 9 in 9 years out of 10, after April 23 in half of the years, after May 6 in 1 year out of 10. Fall: the first frost comes before October 3 in 1 year out of 10, before October 17 in half of the years, before November 1 in 9 years out of 10. Typical frost-free season: 177 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 23First frost ~Oct 17Frost season at La Crosse, WISpring: a frost after April 9 in 9 years out of 10, after April 23 in half of the years, after May 6 in 1 year out of 10. Fall: the first frost comes before October 3 in 1 year out of 10, before October 17 in half of the years, before November 1 in 9 years out of 10. Typical frost-free season: 177 days.JFMAMJJASONDLast frost ~Apr 23First frost ~Oct 17
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 28 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 6October 3
50% (typical)April 23October 17
90% (likely)April 9November 1
Frost-free season (32°F, 50% chance)
177 days
Hard frost (28°F), last in spring, 50% chance after
April 12
Hard frost (28°F), first in fall, 50% chance before
October 28

The last 15 years (2006–2020 normals)

Typical last frost April 24 (1 day later than the 30-year normal), typical first fall frost October 17. Frost-free season 177 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 La Crosse: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 6, 20% May 2, 30% April 30, 40% April 27, 50% April 23, 60% April 20, 70% April 17, 80% April 14, 90% April 9. Observed last spring frost in recent years: 2021 May 11, 2022 April 26, 2023 April 26, 2024 April 24, 2025 April 20, 2026 May 7.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 6Apr 23Apr 92021: May 112022: April 262023: April 262024: April 242025: April 202026: May 7Fall at La Crosse: chance of a frost before this dateFall, chance of a frost before the date: 10% October 3, 20% October 8, 30% October 11, 40% October 14, 50% October 17, 60% October 20, 70% October 23, 80% October 27, 90% November 1. Observed first fall frost in recent years: 2021 October 23, 2022 October 18, 2023 October 29, 2024 October 15, 2025 October 23.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 3Oct 17Nov 12021: October 232022: October 182023: October 292024: October 152025: October 23
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 11October 23
2022April 26October 18
2023April 26October 29
2024April 24October 15
2025April 20October 23
2026May 7season not over yet

What these dates mean

Planting tender crops on April 9 in La Crosse carries a 90 % chance of a light frost and is therefore a gamble. The cautious spring date for setting out those crops is May 6, when only a 10 % chance of a later frost remains.

The 50 % date in spring is April 23, a 50 % chance of a frost later than this date; the 50 % date in fall is October 17, a 50 % chance of a frost earlier than this date. For a cautious fall schedule the date to finish harvesting tender crops is October 3, where only a 10 % chance of an earlier frost exists. The median hard-frost dates are April 12 in spring and October 28 in fall, and a hard frost at 28 °F can damage plant tissue that survives 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 6" 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 3" 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 La Crosse, WINumbered nearest stations: 1 — near Trempealeau, WI — 12 mi; 2 — Caledonia, MN — 21 mi; 3 — Genoa Dam 8, WI — 21 mi; 4 — Sparta, WI — 22 mi; 5 — near Winona, MN — 25 mi.MNIA25 mi · 40 km1. near Trempealeau, WI — 12 mi12. Caledonia, MN — 21 mi23. Genoa Dam 8, WI — 21 mi34. Sparta, WI — 22 mi45. near Winona, MN — 25 mi5
  1. near Trempealeau, WI 12 mi (20 km)
  2. Caledonia, MN 21 mi (34 km)
  3. Genoa Dam 8, WI 21 mi (34 km)
  4. Sparta, WI 22 mi (36 km)
  5. near Winona, MN 25 mi (41 km)

Sources

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

Station coordinates: 43.8789, -91.2528.