U.S. Frost Dates by Weather Station

NOAA station USC00210075 · Minnesota

Frost Dates for Albert Lea, MN

NOAA weather station Albert Lea 3 SE (USC00210075), Minnesota · elevation 1230 ft (375 m) · hardiness zone 5a*

  • Lower-risk planting dateafter May 10only 1 spring in 10 still has a frost later
  • Typical last frostApril 2750% chance of a frost after it
  • Typical first fall frostOctober 950% chance of a frost before it
  • Frost-free season164 daystypical year, 32°F
  • Hardiness zone5acalculated*

The year at a glance

Frost season at Albert Lea, MNSpring: a frost after April 12 in 9 years out of 10, after April 27 in half of the years, after May 10 in 1 year out of 10. Fall: the first frost comes before September 26 in 1 year out of 10, before October 9 in half of the years, before October 23 in 9 years out of 10. Typical frost-free season: 164 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 27First frost ~Oct 9Frost season at Albert Lea, MNSpring: a frost after April 12 in 9 years out of 10, after April 27 in half of the years, after May 10 in 1 year out of 10. Fall: the first frost comes before September 26 in 1 year out of 10, before October 9 in half of the years, before October 23 in 9 years out of 10. Typical frost-free season: 164 days.JFMAMJJASONDLast frost ~Apr 27First frost ~Oct 9
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 30 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 10September 26
50% (typical)April 27October 9
90% (likely)April 12October 23
Frost-free season (32°F, 50% chance)
164 days
Hard frost (28°F), last in spring, 50% chance after
April 15
Hard frost (28°F), first in fall, 50% chance before
October 19

The last 15 years (2006–2020 normals)

Typical last frost April 28 (1 day later than the 30-year normal), typical first fall frost October 13 (4 days later). Frost-free season 167 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 Albert Lea: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 10, 20% May 6, 30% May 3, 40% April 30, 50% April 27, 60% April 24, 70% April 21, 80% April 17, 90% April 12. Observed last spring frost in recent years: 2021 April 25, 2022 April 19, 2023 May 3, 2024 April 24, 2025 April 16, 2026 May 11.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 10Apr 27Apr 122021: April 252022: April 192023: May 32024: April 242025: April 162026: May 11Fall at Albert Lea: chance of a frost before this dateFall, chance of a frost before the date: 10% September 26, 20% October 1, 30% October 4, 40% October 7, 50% October 9, 60% October 12, 70% October 15, 80% October 19, 90% October 23. Observed first fall frost in recent years: 2021 October 22, 2022 September 28, 2023 October 10, 2024 October 16, 2025 October 23.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 26Oct 9Oct 232021: October 222022: September 282023: October 102024: October 162025: October 23
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
2021April 25October 22
2022April 19September 28
2023May 3October 10
2024April 24October 16
2025April 16October 23
2026May 11season not over yet

What these dates mean

May 10 is the cautious spring light-frost date for Albert Lea, carrying only a 10 % chance of a frost later and giving a gardener a reliable point to set out tender crops. The 50% date is April 27, meaning a 50 % chance of a frost later than this point.

September 26 is the cautious fall light-frost date, with a 10 % chance of a frost earlier and marking a sensible time to finish harvesting tender crops. The 50% date is October 9, meaning a 50 % chance of a frost earlier than this point.

Hard-frost dates, April 15 in spring and October 19 in fall, matter more than the 32 °F dates because a temperature of 28 °F can kill plants that survive a light frost.

How to read the probabilities

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

  • Spring: "10% after May 10" 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 Albert Lea, MNNumbered nearest stations: 1 — Northwood, IA — 12 mi; 2 — Austin, MN — 17 mi; 3 — Forest City, IA — 28 mi; 4 — Mason City, IA — 31 mi; 5 — Mason City (Airport), IA — 31 mi.MN25 mi · 40 km1. Northwood, IA — 12 mi12. Austin, MN — 17 mi23. Forest City, IA — 28 mi34. Mason City, IA — 31 mi45. Mason City (Airport), IA — 31 mi5
  1. Northwood, IA 12 mi (20 km)
  2. Austin, MN 17 mi (27 km)
  3. Forest City, IA 28 mi (45 km)
  4. Mason City, IA 31 mi (50 km)
  5. Mason City (Airport), IA 31 mi (50 km)

Sources

* Hardiness zone 5a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 43.6064, -93.3019.