U.S. Frost Dates by Weather Station

NOAA station USC00473022 · Wisconsin

Frost Dates for Gays Mills, WI

NOAA weather station Gays Mills (USC00473022), Wisconsin · elevation 689 ft (210 m) · hardiness zone 4b*

  • Lower-risk planting dateafter May 18only 1 spring in 10 still has a frost later
  • Typical last frostMay 350% chance of a frost after it
  • Typical first fall frostOctober 750% chance of a frost before it
  • Frost-free season156 daystypical year, 32°F
  • Hardiness zone4bcalculated*

The year at a glance

Frost season at Gays Mills, WISpring: a frost after April 19 in 9 years out of 10, after May 3 in half of the years, after May 18 in 1 year out of 10. Fall: the first frost comes before September 25 in 1 year out of 10, before October 7 in half of the years, before October 20 in 9 years out of 10. Typical frost-free season: 156 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 3First frost ~Oct 7Frost season at Gays Mills, WISpring: a frost after April 19 in 9 years out of 10, after May 3 in half of the years, after May 18 in 1 year out of 10. Fall: the first frost comes before September 25 in 1 year out of 10, before October 7 in half of the years, before October 20 in 9 years out of 10. Typical frost-free season: 156 days.JFMAMJJASONDLast frost ~May 3First frost ~Oct 7
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 26 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 18September 25
50% (typical)May 3October 7
90% (likely)April 19October 20
Frost-free season (32°F, 50% chance)
156 days
Hard frost (28°F), last in spring, 50% chance after
April 24
Hard frost (28°F), first in fall, 50% chance before
October 18

The last 15 years (2006–2020 normals)

Typical last frost May 3 (same as the 30-year normal), typical first fall frost October 11 (4 days later). Frost-free season 158 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 Gays Mills: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 18, 20% May 13, 30% May 9, 40% May 6, 50% May 3, 60% April 30, 70% April 28, 80% April 25, 90% April 19. Observed last spring frost in recent years: 2021 May 29, 2022 May 23, 2023 May 3, 2024 April 25, 2025 May 9, 2026 May 12.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 18May 3Apr 192021: May 292022: May 232023: May 32024: April 252025: May 92026: May 12Fall at Gays Mills: chance of a frost before this dateFall, chance of a frost before the date: 10% September 25, 20% September 30, 30% October 2, 40% October 5, 50% October 7, 60% October 10, 70% October 12, 80% October 16, 90% October 20. Observed first fall frost in recent years: 2021 October 17, 2022 September 28, 2023 October 10, 2024 October 7, 2025 October 9.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 25Oct 7Oct 202021: October 172022: September 282023: October 102024: October 72025: October 9
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 29October 17
2022May 23September 28
2023May 3October 10
2024April 25October 7
2025May 9October 9
2026May 12season not over yet

What these dates mean

The 156 days between the 50% dates in Gays Mills frame the period in which most garden work can be scheduled.

The median light-frost dates are May 3 and October 7; a gardener can expect an even chance of a 32 °F frost on May 3 in spring and on October 7 in fall. The cautious spring date for setting out tender crops is May 18, when only a 10 % chance of a later frost remains, while the cautious fall date to finish harvesting tender crops is September 25, when there is only a 10 % chance that a frost has already arrived.

Hard frosts, recorded at the 28 °F threshold, have their own median dates of April 24 and October 18, and they matter more because temperatures that low can damage or kill tender plants that survive a light frost.

How to read the probabilities

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

  • Spring: "10% after May 18" 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 September 25" 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 Gays Mills, WINumbered nearest stations: 1 — Lynxville Dam 9, WI — 14 mi; 2 — Viroqua, WI — 17 mi; 3 — Prairie Du Chien, WI — 23 mi; 4 — Genoa Dam 8, WI — 26 mi; 5 — Lancaster, WI — 34 mi.WIIAMNIL25 mi · 40 km1. Lynxville Dam 9, WI — 14 mi12. Viroqua, WI — 17 mi23. Prairie Du Chien, WI — 23 mi34. Genoa Dam 8, WI — 26 mi45. Lancaster, WI — 34 mi5
  1. Lynxville Dam 9, WI 14 mi (23 km)
  2. Viroqua, WI 17 mi (27 km)
  3. Prairie Du Chien, WI 23 mi (37 km)
  4. Genoa Dam 8, WI 26 mi (42 km)
  5. Lancaster, WI 34 mi (54 km)

Sources

* Hardiness zone 4b: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 43.3144, -90.8486.