U.S. Frost Dates by Weather Station

NOAA station USW00024013 · North Dakota

Frost Dates for Minot (Airport), ND

NOAA weather station Minot International Airport (USW00024013), North Dakota · elevation 1665 ft (508 m) · hardiness zone 4a*

  • Lower-risk planting dateafter May 22only 1 spring in 10 still has a frost later
  • Typical last frostMay 1050% chance of a frost after it
  • Typical first fall frostOctober 150% chance of a frost before it
  • Frost-free season144 daystypical year, 32°F
  • Hardiness zone4acalculated*

The year at a glance

Frost season at Minot (Airport), NDSpring: a frost after April 27 in 9 years out of 10, after May 10 in half of the years, after May 22 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 14 in 9 years out of 10. Typical frost-free season: 144 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 10First frost ~Oct 1Frost season at Minot (Airport), NDSpring: a frost after April 27 in 9 years out of 10, after May 10 in half of the years, after May 22 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 14 in 9 years out of 10. Typical frost-free season: 144 days.JFMAMJJASONDLast frost ~May 10First 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 30 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 22September 19
50% (typical)May 10October 1
90% (likely)April 27October 14
Frost-free season (32°F, 50% chance)
144 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 earlier than the 30-year normal), typical first fall frost October 5 (4 days later). Frost-free season 148 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 Minot (Airport): chance of a frost after this dateSpring, chance of a frost after the date: 10% May 22, 20% May 18, 30% May 15, 40% May 13, 50% May 10, 60% May 7, 70% May 4, 80% May 1, 90% April 27. Observed last spring frost in recent years: 2021 May 10, 2022 May 3, 2023 May 2, 2024 May 5, 2025 May 17, 2026 May 10.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 22May 10Apr 272021: May 102022: May 32023: May 22024: May 52025: May 172026: May 10Fall at Minot (Airport): chance of a frost before this dateFall, chance of a frost before the date: 10% September 19, 20% September 23, 30% September 27, 40% September 29, 50% October 1, 60% October 3, 70% October 6, 80% October 9, 90% October 14. Observed first fall frost in recent years: 2021 October 20, 2022 September 22, 2023 October 6, 2024 October 14, 2025 October 6.Fall: first frostChance of a frost before this date10%50%90%Oct 1Sep 19Oct 1Oct 142021: October 202022: September 222023: October 62024: October 142025: October 6
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 10October 20
2022May 3September 22
2023May 2October 6
2024May 5October 14
2025May 17October 6
2026May 10season not over yet

What these dates mean

September 19 is the cautious date to finish harvesting tender crops in Minot (Airport). Gardeners who aim to avoid a light frost will plan to complete the harvest by that day, since only a 10 % chance of a frost exists earlier.

The median 50 % date for light frost in spring is May 10 and in fall is October 1; each marks an even chance of a frost occurring later (spring) or earlier (fall). The hard-frost median dates are April 30 in spring and October 10 in fall, indicating a 50 % likelihood that temperatures will reach 28 °F on those days. These points help gauge the window when crops are most vulnerable to severe cold.

For a cautious spring schedule, May 22 is the date to set out tender crops, carrying only a 10 % chance of a later light frost. A hard frost matters more than a light frost because 28 °F can damage plant tissue that survives 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 22" 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 Minot (Airport), NDNumbered nearest stations: 1 — near Minot, ND — 5 mi; 2 — Max, ND — 30 mi; 3 — Upham, ND — 35 mi; 4 — Towner, ND — 41 mi; 5 — Garrison, ND — 42 mi.ND25 mi · 40 km1. near Minot, ND — 5 mi12. Max, ND — 30 mi23. Upham, ND — 35 mi34. Towner, ND — 41 mi45. Garrison, ND — 42 mi5
  1. near Minot, ND 5 mi (9 km)
  2. Max, ND 30 mi (48 km)
  3. Upham, ND 35 mi (57 km)
  4. Towner, ND 41 mi (67 km)
  5. Garrison, ND 42 mi (68 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: 48.2553, -101.2733.