U.S. Frost Dates by Weather Station

NOAA station USC00212842 · Minnesota

Frost Dates for Floodwood, MN

NOAA weather station Floodwood 3 NE (USC00212842), Minnesota · elevation 1260 ft (384 m) · hardiness zone 3b*

  • Lower-risk planting dateafter June 13only 1 spring in 10 still has a frost later
  • Typical last frostMay 2950% chance of a frost after it
  • Typical first fall frostSeptember 1850% chance of a frost before it
  • Frost-free season111 daystypical year, 32°F
  • Hardiness zone3bcalculated*

The year at a glance

Frost season at Floodwood, MNSpring: a frost after May 14 in 9 years out of 10, after May 29 in half of the years, after June 13 in 1 year out of 10. Fall: the first frost comes before September 1 in 1 year out of 10, before September 18 in half of the years, before October 2 in 9 years out of 10. Typical frost-free season: 111 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 29First frost ~Sep 18Frost season at Floodwood, MNSpring: a frost after May 14 in 9 years out of 10, after May 29 in half of the years, after June 13 in 1 year out of 10. Fall: the first frost comes before September 1 in 1 year out of 10, before September 18 in half of the years, before October 2 in 9 years out of 10. Typical frost-free season: 111 days.JFMAMJJASONDLast frost ~May 29First frost ~Sep 18
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 28 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)June 13September 1
50% (typical)May 29September 18
90% (likely)May 14October 2
Frost-free season (32°F, 50% chance)
111 days
Hard frost (28°F), last in spring, 50% chance after
May 16
Hard frost (28°F), first in fall, 50% chance before
September 29

The last 15 years (2006–2020 normals)

Typical last frost May 28 (1 day earlier than the 30-year normal), typical first fall frost September 20 (2 days later). Frost-free season 112 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 Floodwood: chance of a frost after this dateSpring, chance of a frost after the date: 10% June 13, 20% June 7, 30% June 3, 40% May 31, 50% May 29, 60% May 26, 70% May 23, 80% May 19, 90% May 14. Observed last spring frost in recent years: 2021 May 29, 2022 May 17, 2023 May 3, 2024 May 5, 2025 May 25, 2026 May 20.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1Jun 13May 29May 142021: May 292022: May 172023: May 32024: May 52025: May 252026: May 20Fall at Floodwood: chance of a frost before this dateFall, chance of a frost before the date: 10% September 1, 20% September 6, 30% September 11, 40% September 15, 50% September 18, 60% September 21, 70% September 24, 80% September 28, 90% October 2. Observed first fall frost in recent years: 2021 September 22, 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 1Sep 18Oct 22021: September 222022: 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 29September 22
2022May 17September 27
2023May 3September 13
2024May 5September 7
2025May 25October 8
2026May 20season not over yet

What these dates mean

There are 111 days between the 32°F 50% dates in Floodwood, and within that span gardeners can plan for the period when light frosts are most uncertain. The 50% date in spring is May 29, which means there is a 50% chance of a light frost later than this date; the 50% date in fall is September 18, giving a 50% chance of a light frost earlier than this date. For a cautious approach, the spring June 13 date carries a 10% chance of a frost later and is used for setting out tender crops, while the fall September 1 date has a 10% chance of a frost earlier and guides the finish of tender-crop harvests. A hard frost, recorded at 28°F, is more damaging than a light frost at 32°F, and its 50% dates are May 16 in spring and September 29 in fall.

How to read the probabilities

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

  • Spring: "10% after June 13" 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 1" 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 Floodwood, MNNumbered nearest stations: 1 — Wright, MN — 21 mi; 2 — Cloquet, MN — 25 mi; 3 — near Hibbing, MN — 29 mi; 4 — near Grand Rapids, MN — 35 mi; 5 — Eveleth, MN — 37 mi.MNWI25 mi · 40 km1. Wright, MN — 21 mi12. Cloquet, MN — 25 mi23. near Hibbing, MN — 29 mi34. near Grand Rapids, MN — 35 mi45. Eveleth, MN — 37 mi5
  1. Wright, MN 21 mi (33 km)
  2. Cloquet, MN 25 mi (40 km)
  3. near Hibbing, MN 29 mi (46 km)
  4. near Grand Rapids, MN 35 mi (56 km)
  5. Eveleth, MN 37 mi (60 km)

Sources

* Hardiness zone 3b: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 46.9728, -92.87.