U.S. Frost Dates by Weather Station

NOAA station USC00211630 · Minnesota

Frost Dates for Cloquet, MN

NOAA weather station Cloquet (USC00211630), Minnesota · elevation 1265 ft (386 m) · hardiness zone 4a*

  • Lower-risk planting dateafter June 9only 1 spring in 10 still has a frost later
  • Typical last frostMay 2650% chance of a frost after it
  • Typical first fall frostSeptember 2350% chance of a frost before it
  • Frost-free season118 daystypical year, 32°F
  • Hardiness zone4acalculated*

The year at a glance

Frost season at Cloquet, MNSpring: a frost after May 13 in 9 years out of 10, after May 26 in half of the years, after June 9 in 1 year out of 10. Fall: the first frost comes before September 9 in 1 year out of 10, before September 23 in half of the years, before October 4 in 9 years out of 10. Typical frost-free season: 118 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 26First frost ~Sep 23Frost season at Cloquet, MNSpring: a frost after May 13 in 9 years out of 10, after May 26 in half of the years, after June 9 in 1 year out of 10. Fall: the first frost comes before September 9 in 1 year out of 10, before September 23 in half of the years, before October 4 in 9 years out of 10. Typical frost-free season: 118 days.JFMAMJJASONDLast frost ~May 26First frost ~Sep 23
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 29 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)June 9September 9
50% (typical)May 26September 23
90% (likely)May 13October 4
Frost-free season (32°F, 50% chance)
118 days
Hard frost (28°F), last in spring, 50% chance after
May 12
Hard frost (28°F), first in fall, 50% chance before
October 3

The last 15 years (2006–2020 normals)

Typical last frost May 25 (1 day earlier than the 30-year normal), typical first fall frost September 21 (2 days earlier). Frost-free season 118 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 Cloquet: chance of a frost after this dateSpring, chance of a frost after the date: 10% June 9, 20% June 4, 30% June 1, 40% May 30, 50% May 26, 60% May 24, 70% May 21, 80% May 18, 90% May 13. Observed last spring frost in recent years: 2021 May 29, 2022 May 21, 2023 May 15, 2024 May 11, 2025 May 25, 2026 May 21.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1Jun 9May 26May 132021: May 292022: May 212023: May 152024: May 112025: May 252026: May 21Fall at Cloquet: chance of a frost before this dateFall, chance of a frost before the date: 10% September 9, 20% September 14, 30% September 18, 40% September 20, 50% September 23, 60% September 26, 70% September 28, 80% October 1, 90% October 4. Observed first fall frost in recent years: 2021 October 17, 2022 September 27, 2023 September 13, 2024 September 7, 2025 October 8.Fall: first frostChance of a frost before this date10%50%90%Sep 1Oct 1Sep 9Sep 23Oct 42021: October 172022: September 272023: September 132024: September 72025: October 8
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 21September 27
2023May 15September 13
2024May 11September 7
2025May 25October 8
2026May 21season not over yet

What these dates mean

June 9 is the cautious spring light-frost date for Cloquet, carrying only a 10 % chance that a frost will occur later; a gardener can plan to set out tender crops after that day.

The 50% date in spring is May 26, which means a 50 % chance of a frost later than this date, while the 90 % chance date of May 13 is a gamble for early planting. In the fall the cautious light-frost date is September 9, with only a 10 % chance that a frost has arrived earlier, allowing growers to finish harvesting tender crops. The 50% date in fall is September 23, which means a 50 % chance of a frost earlier than this date, and the October 4 date carries a 90 % chance of a frost before it, a gamble for late crops.

Hard-frost dates are May 12 in spring and October 3 in fall; a hard frost at 28 °F can damage plant tissue that survives a light frost, making it a more critical threshold for growers.

How to read the probabilities

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

  • Spring: "10% after June 9" 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 9" 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 Cloquet, MNNumbered nearest stations: 1 — Wright, MN — 20 mi; 2 — Superior, WI — 21 mi; 3 — Moose Lake, MN — 22 mi; 4 — Floodwood, MN — 25 mi; 5 — Bruno, MN — 28 mi.WI25 mi · 40 km1. Wright, MN — 20 mi12. Superior, WI — 21 mi23. Moose Lake, MN — 22 mi34. Floodwood, MN — 25 mi45. Bruno, MN — 28 mi5
  1. Wright, MN 20 mi (33 km)
  2. Superior, WI 21 mi (35 km)
  3. Moose Lake, MN 22 mi (35 km)
  4. Floodwood, MN 25 mi (40 km)
  5. Bruno, MN 28 mi (45 km)

Sources

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

Station coordinates: 46.7053, -92.5239.