U.S. Frost Dates by Weather Station

NOAA station USW00094967 · Minnesota

Frost Dates for Park Rapids, MN

NOAA weather station Park Rapids Municipal Airport (USW00094967), Minnesota · elevation 1434 ft (437 m) · hardiness zone 3b*

  • Lower-risk planting dateafter May 27only 1 spring in 10 still has a frost later
  • Typical last frostMay 1450% chance of a frost after it
  • Typical first fall frostSeptember 2550% chance of a frost before it
  • Frost-free season133 daystypical year, 32°F
  • Hardiness zone3bcalculated*

The year at a glance

Frost season at Park Rapids, MNSpring: a frost after May 1 in 9 years out of 10, after May 14 in half of the years, after May 27 in 1 year out of 10. Fall: the first frost comes before September 12 in 1 year out of 10, before September 25 in half of the years, before October 8 in 9 years out of 10. Typical frost-free season: 133 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 14First frost ~Sep 25Frost season at Park Rapids, MNSpring: a frost after May 1 in 9 years out of 10, after May 14 in half of the years, after May 27 in 1 year out of 10. Fall: the first frost comes before September 12 in 1 year out of 10, before September 25 in half of the years, before October 8 in 9 years out of 10. Typical frost-free season: 133 days.JFMAMJJASONDLast frost ~May 14First frost ~Sep 25
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 27September 12
50% (typical)May 14September 25
90% (likely)May 1October 8
Frost-free season (32°F, 50% chance)
133 days
Hard frost (28°F), last in spring, 50% chance after
May 4
Hard frost (28°F), first in fall, 50% chance before
October 4

The last 15 years (2006–2020 normals)

Typical last frost May 13 (1 day earlier than the 30-year normal), typical first fall frost September 29 (4 days later). Frost-free season 136 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 Park Rapids: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 27, 20% May 22, 30% May 18, 40% May 16, 50% May 14, 60% May 11, 70% May 8, 80% May 5, 90% May 1. Observed last spring frost in recent years: 2021 May 28, 2022 May 22, 2023 May 3, 2024 April 24, 2025 May 22, 2026 May 20.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 27May 14May 12021: May 282022: May 222023: May 32024: April 242025: May 222026: May 20Fall at Park Rapids: chance of a frost before this dateFall, chance of a frost before the date: 10% September 12, 20% September 17, 30% September 20, 40% September 23, 50% September 25, 60% September 28, 70% September 30, 80% October 3, 90% October 8. Observed first fall frost in recent years: 2021 October 16, 2022 September 27, 2023 October 9, 2024 October 14, 2025 September 7.Fall: first frostChance of a frost before this date10%50%90%Sep 1Oct 1Sep 12Sep 25Oct 82021: October 162022: September 272023: October 92024: October 142025: September 7
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 28October 16
2022May 22September 27
2023May 3October 9
2024April 24October 14
2025May 22September 7
2026May 20season not over yet

What these dates mean

Setting tender crops on May 1 in Park Rapids carries a 90% chance of a frost later, so it is a gamble for gardeners.

A cautious plan would wait until May 27, the date with only a 10% chance of a later frost, to set out tender crops in spring, and until September 12, the date with only a 10% chance of an earlier frost, to finish harvesting tender crops in fall. The 50% date is May 14, and the 50% date is September 25; at those points frost is equally likely to occur later (spring) or earlier (fall). The 50% hard-frost dates are May 4 and October 4, and a hard frost at 28 °F can injure plants that survive a light frost at 32 °F.

How to read the probabilities

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

  • Spring: "10% after May 27" 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 12" 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 Park Rapids, MNNumbered nearest stations: 1 — Itasca University of Minn, MN — 23 mi; 2 — Cass Lake, MN — 40 mi; 3 — Leech Lake, MN — 46 mi; 4 — near East Gull Lake, MN — 48 mi; 5 — near Crosslake, MN — 48 mi.MN25 mi · 40 km1. Itasca University of Minn, MN — 23 mi12. Cass Lake, MN — 40 mi23. Leech Lake, MN — 46 mi34. near East Gull Lake, MN — 48 mi45. near Crosslake, MN — 48 mi5
  1. Itasca University of Minn, MN 23 mi (37 km)
  2. Cass Lake, MN 40 mi (64 km)
  3. Leech Lake, MN 46 mi (75 km)
  4. near East Gull Lake, MN 48 mi (77 km)
  5. near Crosslake, MN 48 mi (77 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: 46.9006, -95.0678.