U.S. Frost Dates by Weather Station

NOAA station USC00215838 · Minnesota

Frost Dates for New Hope, MN

NOAA weather station New Hope (USC00215838), Minnesota · elevation 910 ft (277 m) · hardiness zone 5a*

  • Lower-risk planting dateafter May 12only 1 spring in 10 still has a frost later
  • Typical last frostApril 2950% chance of a frost after it
  • Typical first fall frostOctober 1250% chance of a frost before it
  • Frost-free season163 daystypical year, 32°F
  • Hardiness zone5acalculated*

The year at a glance

Frost season at New Hope, MNSpring: a frost after April 15 in 9 years out of 10, after April 29 in half of the years, after May 12 in 1 year out of 10. Fall: the first frost comes before September 29 in 1 year out of 10, before October 12 in half of the years, before October 25 in 9 years out of 10. Typical frost-free season: 163 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 29First frost ~Oct 12Frost season at New Hope, MNSpring: a frost after April 15 in 9 years out of 10, after April 29 in half of the years, after May 12 in 1 year out of 10. Fall: the first frost comes before September 29 in 1 year out of 10, before October 12 in half of the years, before October 25 in 9 years out of 10. Typical frost-free season: 163 days.JFMAMJJASONDLast frost ~Apr 29First frost ~Oct 12
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 27 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 12September 29
50% (typical)April 29October 12
90% (likely)April 15October 25
Frost-free season (32°F, 50% chance)
163 days
Hard frost (28°F), last in spring, 50% chance after
April 19
Hard frost (28°F), first in fall, 50% chance before
October 22

The last 15 years (2006–2020 normals)

Typical last frost April 29 (same as the 30-year normal), typical first fall frost October 14 (2 days later). Frost-free season 168 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 New Hope: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 12, 20% May 7, 30% May 4, 40% May 1, 50% April 29, 60% April 26, 70% April 23, 80% April 19, 90% April 15. Observed last spring frost in recent years: 2021 May 11, 2022 April 27, 2023 April 26, 2024 April 24, 2025 April 8, 2026 May 7.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 12Apr 29Apr 152021: May 112022: April 272023: April 262024: April 242025: April 82026: May 7Fall at New Hope: chance of a frost before this dateFall, chance of a frost before the date: 10% September 29, 20% October 2, 30% October 5, 40% October 9, 50% October 12, 60% October 15, 70% October 18, 80% October 21, 90% October 25. Observed first fall frost in recent years: 2021 October 22, 2022 October 8, 2023 October 27, 2024 October 15, 2025 October 8.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 29Oct 12Oct 252021: October 222022: October 82023: October 272024: 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 22
2022April 27October 8
2023April 26October 27
2024April 24October 15
2025April 8October 8
2026May 7season not over yet

What these dates mean

The 163 days between the 50% dates in New Hope—April 29 and October 12—frame the window when a light frost (32 °F) is equally likely to happen before or after each date. For a gardener, these median dates mark the point of even odds, providing a reference for the overall frost risk over the 27-year record.

In spring, the cautious date for setting out tender crops is May 12, which carries a 10 % chance of a later frost, while planting on April 15 involves a 90 % chance of a frost and is a gamble. In fall, the cautious date to finish harvesting tender crops is September 29, with a 10 % chance of an earlier frost, whereas October 25 represents a 90 % chance of an earlier frost and is risky. The hard-frost 50% dates are April 19 and October 22.

A hard frost at 28 °F can damage plants more severely 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 12" 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 29" 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 New Hope, MNNumbered nearest stations: 1 — Lower St. Anthony Falls, MN — 7 mi; 2 — near Roseville, MN — 10 mi; 3 — Minneapolis (Minneapolis/St. Paul Airport), MN — 11 mi; 4 — Chanhassen, MN — 14 mi; 5 — Rosemount, MN — 24 mi.WI25 mi · 40 km1. Lower St. Anthony Falls, MN — 7 mi12. near Roseville, MN — 10 mi23. Minneapolis (Minneapolis/St. Paul Airport), MN — 11 mi34. Chanhassen, MN — 14 mi45. Rosemount, MN — 24 mi5
  1. Lower St. Anthony Falls, MN 7 mi (11 km)
  2. near Roseville, MN 10 mi (16 km)
  3. Minneapolis (Minneapolis/St. Paul Airport), MN 11 mi (18 km)
  4. Chanhassen, MN 14 mi (23 km)
  5. Rosemount, MN 24 mi (39 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: 45.01, -93.3792.