U.S. Frost Dates by Weather Station

NOAA station USC00471923 · Wisconsin

Frost Dates for Cumberland, WI

NOAA weather station Cumberland (USC00471923), Wisconsin · elevation 1240 ft (378 m) · hardiness zone 4b*

  • Lower-risk planting dateafter May 18only 1 spring in 10 still has a frost later
  • Typical last frostMay 550% chance of a frost after it
  • Typical first fall frostOctober 450% chance of a frost before it
  • Frost-free season152 daystypical year, 32°F
  • Hardiness zone4bcalculated*

The year at a glance

Frost season at Cumberland, WISpring: a frost after April 22 in 9 years out of 10, after May 5 in half of the years, after May 18 in 1 year out of 10. Fall: the first frost comes before September 23 in 1 year out of 10, before October 4 in half of the years, before October 19 in 9 years out of 10. Typical frost-free season: 152 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 5First frost ~Oct 4Frost season at Cumberland, WISpring: a frost after April 22 in 9 years out of 10, after May 5 in half of the years, after May 18 in 1 year out of 10. Fall: the first frost comes before September 23 in 1 year out of 10, before October 4 in half of the years, before October 19 in 9 years out of 10. Typical frost-free season: 152 days.JFMAMJJASONDLast frost ~May 5First frost ~Oct 4
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.Today

Frost dates (32°F)

Probability of frost, based on 27 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 18September 23
50% (typical)May 5October 4
90% (likely)April 22October 19
Frost-free season (32°F, 50% chance)
152 days
Hard frost (28°F), last in spring, 50% chance after
April 25
Hard frost (28°F), first in fall, 50% chance before
October 16

The last 15 years (2006–2020 normals)

Typical last frost May 4 (1 day earlier than the 30-year normal), typical first fall frost October 10 (6 days later). Frost-free season 157 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 Cumberland: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 18, 20% May 12, 30% May 9, 40% May 7, 50% May 5, 60% May 2, 70% April 30, 80% April 27, 90% April 22. Observed last spring frost in recent years: 2021 May 12, 2022 April 29, 2023 May 3, 2024 April 25, 2025 April 26, 2026 May 2.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 18May 5Apr 222021: May 122022: April 292023: May 32024: April 252025: April 262026: May 2Fall at Cumberland: chance of a frost before this dateFall, chance of a frost before the date: 10% September 23, 20% September 27, 30% September 30, 40% October 1, 50% October 4, 60% October 7, 70% October 10, 80% October 14, 90% October 19. Observed first fall frost in recent years: 2021 October 22, 2022 October 8, 2023 October 17, 2024 October 15, 2025 October 23.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 23Oct 4Oct 192021: October 222022: October 82023: October 172024: 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 12October 22
2022April 29October 8
2023May 3October 17
2024April 25October 15
2025April 26October 23
2026May 2season not over yet

What these dates mean

May 18 marks the cautious spring date in Cumberland; with only a 10 % chance of a light frost later, a gardener can plan to set out tender crops on that day. The 50% date is May 5; at that point there is a 50 % chance of a light frost occurring later in the season. In fall, September 23 is the cautious date, offering a 10 % chance of a light frost earlier and allowing harvest of tender crops to be completed. The 50% date is October 4; at that point there is a 50 % chance of a light frost occurring earlier.

Hard frost at 28 °F can damage plants more severely than a light frost at 32 °F, so the median hard-frost dates—April 25 in spring and October 16 in fall—show when the deeper freeze risk becomes even odds.

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 23" 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 Cumberland, WINumbered nearest stations: 1 — Rice Lake, WI — 15 mi; 2 — Spooner, WI — 21 mi; 3 — Luck, WI — 23 mi; 4 — Ridgeland, WI — 23 mi; 5 — Amery, WI — 23 mi.WIMN25 mi · 40 km1. Rice Lake, WI — 15 mi12. Spooner, WI — 21 mi23. Luck, WI — 23 mi34. Ridgeland, WI — 23 mi45. Amery, WI — 23 mi5
  1. Rice Lake, WI 15 mi (23 km)
  2. Spooner, WI 21 mi (34 km)
  3. Luck, WI 23 mi (36 km)
  4. Ridgeland, WI 23 mi (37 km)
  5. Amery, WI 23 mi (37 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: 45.5331, -92.0225.