U.S. Frost Dates by Weather Station

NOAA station USC00211448 · Minnesota

Frost Dates for Chanhassen, MN

NOAA weather station Chanhassen WSFO (USC00211448), Minnesota · elevation 946 ft (288 m) · hardiness zone 5a*

  • Lower-risk planting dateafter May 15only 1 spring in 10 still has a frost later
  • Typical last frostApril 3050% chance of a frost after it
  • Typical first fall frostOctober 950% chance of a frost before it
  • Frost-free season160 daystypical year, 32°F
  • Hardiness zone5acalculated*

The year at a glance

Frost season at Chanhassen, MNSpring: a frost after April 15 in 9 years out of 10, after April 30 in half of the years, after May 15 in 1 year out of 10. Fall: the first frost comes before September 25 in 1 year out of 10, before October 9 in half of the years, before October 21 in 9 years out of 10. Typical frost-free season: 160 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 30First frost ~Oct 9Frost season at Chanhassen, MNSpring: a frost after April 15 in 9 years out of 10, after April 30 in half of the years, after May 15 in 1 year out of 10. Fall: the first frost comes before September 25 in 1 year out of 10, before October 9 in half of the years, before October 21 in 9 years out of 10. Typical frost-free season: 160 days.JFMAMJJASONDLast frost ~Apr 30First 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.

Frost dates (32°F)

Probability of frost, based on 25 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 15September 25
50% (typical)April 30October 9
90% (likely)April 15October 21
Frost-free season (32°F, 50% chance)
160 days
Hard frost (28°F), last in spring, 50% chance after
April 19
Hard frost (28°F), first in fall, 50% chance before
October 19

The last 15 years (2006–2020 normals)

Typical last frost April 29 (1 day earlier than the 30-year normal), typical first fall frost October 12 (3 days later). Frost-free season 163 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 Chanhassen: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 15, 20% May 9, 30% May 6, 40% May 2, 50% April 30, 60% April 27, 70% April 24, 80% April 20, 90% April 15. Observed last spring frost in recent years: 2021 May 11, 2022 April 27, 2023 May 3, 2024 April 24, 2025 April 26, 2026 May 7.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 15Apr 30Apr 152021: May 112022: April 272023: May 32024: April 242025: April 262026: May 7Fall at Chanhassen: chance of a frost before this dateFall, chance of a frost before the date: 10% September 25, 20% September 30, 30% October 3, 40% October 6, 50% October 9, 60% October 12, 70% October 14, 80% October 17, 90% October 21. Observed first fall frost in recent years: 2021 October 21, 2022 September 28, 2023 October 11, 2024 October 15, 2025 October 8.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 25Oct 9Oct 212021: October 212022: September 282023: October 112024: October 152025: 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 3October 11
2024April 24October 15
2025April 26October 8
2026May 7season not over yet

What these dates mean

Setting out tender crops on April 15 in Chanhassen is a gamble, because there is a 90% chance of a light frost later than that day.

The 50% date in spring, April 30, marks the point where a light frost has a 50% chance of occurring later, and the 50% date in fall, October 9, marks the point where a light frost has a 50% chance of occurring earlier. A cautious plan would use May 15 for planting tender crops, with only a 10% chance of a light frost later, and would aim to finish harvesting tender crops by September 25, which carries only a 10% chance of a light frost earlier.

The 50% hard-frost dates are April 19 and October 19; a hard frost at 28 °F can cause far greater injury than 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 15" 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 25" 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 Chanhassen, MNNumbered nearest stations: 1 — Jordan, MN — 14 mi; 2 — New Hope, MN — 14 mi; 3 — Minneapolis (Minneapolis/St. Paul Airport), MN — 17 mi; 4 — Lower St. Anthony Falls, MN — 18 mi; 5 — near Roseville, MN — 21 mi.WI25 mi · 40 km1. Jordan, MN — 14 mi12. New Hope, MN — 14 mi23. Minneapolis (Minneapolis/St. Paul Airport), MN — 17 mi34. Lower St. Anthony Falls, MN — 18 mi45. near Roseville, MN — 21 mi5
  1. Jordan, MN 14 mi (23 km)
  2. New Hope, MN 14 mi (23 km)
  3. Minneapolis (Minneapolis/St. Paul Airport), MN 17 mi (27 km)
  4. Lower St. Anthony Falls, MN 18 mi (29 km)
  5. near Roseville, MN 21 mi (34 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: 44.8497, -93.5644.