U.S. Frost Dates by Weather Station

NOAA station USC00210287 · Minnesota

Frost Dates for Artichoke Lake 1 E, MN

NOAA weather station Artichoke Lake 1 E (USC00210287), Minnesota · elevation 1098 ft (335 m) · hardiness zone 4b*

  • Lower-risk planting dateafter May 14only 1 spring in 10 still has a frost later
  • Typical last frostMay 150% chance of a frost after it
  • Typical first fall frostOctober 850% chance of a frost before it
  • Frost-free season159 daystypical year, 32°F
  • Hardiness zone4bcalculated*

The year at a glance

Frost season at Artichoke Lake 1 E, MNSpring: a frost after April 17 in 9 years out of 10, after May 1 in half of the years, after May 14 in 1 year out of 10. Fall: the first frost comes before September 26 in 1 year out of 10, before October 8 in half of the years, before October 22 in 9 years out of 10. Typical frost-free season: 159 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 1First frost ~Oct 8Frost season at Artichoke Lake 1 E, MNSpring: a frost after April 17 in 9 years out of 10, after May 1 in half of the years, after May 14 in 1 year out of 10. Fall: the first frost comes before September 26 in 1 year out of 10, before October 8 in half of the years, before October 22 in 9 years out of 10. Typical frost-free season: 159 days.JFMAMJJASONDLast frost ~May 1First frost ~Oct 8
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 29 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 14September 26
50% (typical)May 1October 8
90% (likely)April 17October 22
Frost-free season (32°F, 50% chance)
159 days
Hard frost (28°F), last in spring, 50% chance after
April 21
Hard frost (28°F), first in fall, 50% chance before
October 19

The last 15 years (2006–2020 normals)

Typical last frost May 1 (same as the 30-year normal), typical first fall frost October 11 (3 days later). Frost-free season 160 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 Artichoke Lake 1 E: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 14, 20% May 10, 30% May 6, 40% May 3, 50% May 1, 60% April 29, 70% April 26, 80% April 22, 90% April 17. Observed last spring frost in recent years: 2021 May 11, 2022 April 27, 2023 May 2, 2024 April 24, 2025 April 29, 2026 May 11.Spring: last frostChance of a frost after this date10%50%90%May 1May 14May 1Apr 172021: May 112022: April 272023: May 22024: April 242025: April 292026: May 11Fall at Artichoke Lake 1 E: chance of a frost before this dateFall, chance of a frost before the date: 10% September 26, 20% September 30, 30% October 2, 40% October 5, 50% October 8, 60% October 11, 70% October 14, 80% October 18, 90% October 22. Observed first fall frost in recent years: 2021 October 21, 2022 September 28, 2023 October 7, 2025 October 8.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 26Oct 8Oct 222021: October 212022: September 282023: October 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 11October 21
2022April 27September 28
2023May 2October 7
2024April 24incomplete record
2025April 29October 8
2026May 11season not over yet

What these dates mean

The cautious fall date for finishing the harvest in Artichoke Lake 1 E is September 26, when there is only a 10 % chance that a light frost has arrived.

For gardeners the 50 % dates indicate the moment a light frost is equally likely either way. The 50 % date is May 1 and the 50 % date is October 8. The 50 % hard-frost dates are April 21 and October 19, marking the median odds for a 28 °F event. The interval between the two 32°F 50 % dates is 159 days, indicating the median frost-free span.

A cautious planting plan uses the May 14 spring date to set out tender crops and the September 26 fall date to finish harvesting them. Hard frost at 28 °F can damage plants that survive a 32 °F light frost, so it poses a greater risk.

How to read the probabilities

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

  • Spring: "10% after May 14" 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 26" 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 Artichoke Lake 1 E, MNNumbered nearest stations: 1 — near Morris, MN — 19 mi; 2 — Milan, MN — 21 mi; 3 — Benson, MN — 25 mi; 4 — Madison, MN — 27 mi; 5 — Wheaton, MN — 34 mi.SDND25 mi · 40 km1. near Morris, MN — 19 mi12. Milan, MN — 21 mi23. Benson, MN — 25 mi34. Madison, MN — 27 mi45. Wheaton, MN — 34 mi5
  1. near Morris, MN 19 mi (30 km)
  2. Milan, MN 21 mi (33 km)
  3. Benson, MN 25 mi (41 km)
  4. Madison, MN 27 mi (43 km)
  5. Wheaton, MN 34 mi (55 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: 45.3856, -96.1258.