U.S. Frost Dates by Weather Station

NOAA station USC00325710 · North Dakota

Frost Dates for McClusky, ND

NOAA weather station McClusky (USC00325710), North Dakota · elevation 1927 ft (587 m) · hardiness zone 4b*

  • Lower-risk planting dateafter May 20only 1 spring in 10 still has a frost later
  • Typical last frostMay 850% chance of a frost after it
  • Typical first fall frostOctober 150% chance of a frost before it
  • Frost-free season145 daystypical year, 32°F
  • Hardiness zone4bcalculated*

The year at a glance

Frost season at McClusky, NDSpring: a frost after April 25 in 9 years out of 10, after May 8 in half of the years, after May 20 in 1 year out of 10. Fall: the first frost comes before September 19 in 1 year out of 10, before October 1 in half of the years, before October 13 in 9 years out of 10. Typical frost-free season: 145 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 8First frost ~Oct 1Frost season at McClusky, NDSpring: a frost after April 25 in 9 years out of 10, after May 8 in half of the years, after May 20 in 1 year out of 10. Fall: the first frost comes before September 19 in 1 year out of 10, before October 1 in half of the years, before October 13 in 9 years out of 10. Typical frost-free season: 145 days.JFMAMJJASONDLast frost ~May 8First frost ~Oct 1
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 26 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 20September 19
50% (typical)May 8October 1
90% (likely)April 25October 13
Frost-free season (32°F, 50% chance)
145 days
Hard frost (28°F), last in spring, 50% chance after
April 30
Hard frost (28°F), first in fall, 50% chance before
October 10

The last 15 years (2006–2020 normals)

Typical last frost May 9 (1 day later than the 30-year normal), typical first fall frost October 4 (3 days later). Frost-free season 149 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 McClusky: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 20, 20% May 16, 30% May 13, 40% May 10, 50% May 8, 60% May 5, 70% May 3, 80% April 30, 90% April 25. Observed last spring frost in recent years: 2021 May 11, 2022 May 2, 2023 May 1, 2024 May 3, 2025 April 29, 2026 May 9.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 20May 8Apr 252021: May 112022: May 22023: May 12024: May 32025: April 292026: May 9Fall at McClusky: chance of a frost before this dateFall, chance of a frost before the date: 10% September 19, 20% September 23, 30% September 26, 40% September 29, 50% October 1, 60% October 3, 70% October 6, 80% October 9, 90% October 13. Observed first fall frost in recent years: 2021 October 20, 2022 October 5, 2024 October 13, 2025 October 5.Fall: first frostChance of a frost before this date10%50%90%Oct 1Sep 19Oct 1Oct 132021: October 202022: October 52024: October 132025: October 5
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 11October 20
2022May 2October 5
2023May 1incomplete record
2024May 3October 13
2025April 29October 5
2026May 9season not over yet

What these dates mean

September 19 is the cautious fall date for finishing the harvest of tender crops in McClusky, carrying only a 10% chance that a light frost has arrived earlier. In spring the cautious date for setting out tender crops is May 20, when the chance of a frost later than that date is just 10%; planting on April 25 would be a gamble with a 90% chance of frost. The 50% date is May 8, the point at which a light frost is equally likely, and the 50% date is October 1, the median moment for a light frost in fall. The hard-frost 50% dates are April 30 in spring and October 10 in fall; a hard frost at 28 °F can damage vegetation more severely than a light frost at 32 °F because the lower temperature can kill plant tissue that survives a milder chill.

How to read the probabilities

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

  • Spring: "10% after May 20" 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 19" 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 McClusky, NDNumbered nearest stations: 1 — Turtle Lake, ND — 21 mi; 2 — Underwood, ND — 33 mi; 3 — Harvey, ND — 35 mi; 4 — Drake, ND — 40 mi; 5 — Max, ND — 46 mi.ND25 mi · 40 km1. Turtle Lake, ND — 21 mi12. Underwood, ND — 33 mi23. Harvey, ND — 35 mi34. Drake, ND — 40 mi45. Max, ND — 46 mi5
  1. Turtle Lake, ND 21 mi (34 km)
  2. Underwood, ND 33 mi (53 km)
  3. Harvey, ND 35 mi (56 km)
  4. Drake, ND 40 mi (64 km)
  5. Max, ND 46 mi (74 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: 47.4825, -100.4444.