U.S. Frost Dates by Weather Station

NOAA station USC00474174 · Wisconsin

Frost Dates for Kenosha, WI

NOAA weather station Kenosha (USC00474174), Wisconsin · elevation 600 ft (183 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 3only 1 spring in 10 still has a frost later
  • Typical last frostApril 1950% chance of a frost after it
  • Typical first fall frostOctober 2650% chance of a frost before it
  • Frost-free season189 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Kenosha, WISpring: a frost after April 6 in 9 years out of 10, after April 19 in half of the years, after May 3 in 1 year out of 10. Fall: the first frost comes before October 11 in 1 year out of 10, before October 26 in half of the years, before November 9 in 9 years out of 10. Typical frost-free season: 189 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 19First frost ~Oct 26Frost season at Kenosha, WISpring: a frost after April 6 in 9 years out of 10, after April 19 in half of the years, after May 3 in 1 year out of 10. Fall: the first frost comes before October 11 in 1 year out of 10, before October 26 in half of the years, before November 9 in 9 years out of 10. Typical frost-free season: 189 days.JFMAMJJASONDLast frost ~Apr 19First frost ~Oct 26
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 3October 11
50% (typical)April 19October 26
90% (likely)April 6November 9
Frost-free season (32°F, 50% chance)
189 days
Hard frost (28°F), last in spring, 50% chance after
April 8
Hard frost (28°F), first in fall, 50% chance before
November 6

The last 15 years (2006–2020 normals)

Typical last frost April 20 (1 day later than the 30-year normal), typical first fall frost October 27 (1 day later). Frost-free season 190 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 Kenosha: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 3, 20% April 29, 30% April 25, 40% April 22, 50% April 19, 60% April 16, 70% April 13, 80% April 11, 90% April 6. Observed last spring frost in recent years: 2021 April 22, 2022 April 27, 2023 April 26, 2024 April 25, 2025 April 16.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 3Apr 19Apr 62021: April 222022: April 272023: April 262024: April 252025: April 16Fall at Kenosha: chance of a frost before this dateFall, chance of a frost before the date: 10% October 11, 20% October 18, 30% October 21, 40% October 24, 50% October 26, 60% October 29, 70% November 1, 80% November 4, 90% November 9. Observed first fall frost in recent years: 2021 November 2, 2022 October 19, 2023 October 30, 2024 November 20, 2025 October 24.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 11Oct 26Nov 92021: November 22022: October 192023: October 302024: November 202025: 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
2021April 22November 2
2022April 27October 19
2023April 26October 30
2024April 25November 20
2025April 16October 24
2026incomplete recordseason not over yet

What these dates mean

The cautious fall date for finishing the harvest in Kenosha is October 11, when there is only a 10% chance that a light frost has arrived. The 50% light-frost date in fall is October 26; on that day there is an even chance of a frost earlier than this date.

Spring gardeners looking to set out tender crops should use the cautious date of May 3, which carries a 10% chance of a frost later than that day, while the 50% light-frost date is April 19, indicating an even chance of a frost later than this date. The 90% date, April 6, is a gamble for early planting.

Hard-frost conditions at 28 °F are more damaging than light frosts; the 50% hard-frost dates are April 8 in spring and November 6 in fall, marking the points where there is an even chance of a hard 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 3" 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 11" 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 Kenosha, WINumbered nearest stations: 1 — Racine, WI — 10 mi; 2 — Burlington, WI — 23 mi; 3 — near Milwaukee, WI — 28 mi; 4 — near McHenry, IL — 28 mi; 5 — Chicago Botanic Garden, IL — 29 mi.WIILMI25 mi · 40 km1. Racine, WI — 10 mi12. Burlington, WI — 23 mi23. near Milwaukee, WI — 28 mi34. near McHenry, IL — 28 mi45. Chicago Botanic Garden, IL — 29 mi5
  1. Racine, WI 10 mi (16 km)
  2. Burlington, WI 23 mi (37 km)
  3. near Milwaukee, WI 28 mi (44 km)
  4. near McHenry, IL 28 mi (46 km)
  5. Chicago Botanic Garden, IL 29 mi (47 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: 42.5608, -87.8156.