U.S. Frost Dates by Weather Station

NOAA station USC00426181 · Utah

Frost Dates for New Harmony, UT

NOAA weather station New Harmony (USC00426181), Utah · elevation 5167 ft (1575 m) · hardiness zone 7a*

  • Lower-risk planting dateafter May 29only 1 spring in 10 still has a frost later
  • Typical last frostMay 950% chance of a frost after it
  • Typical first fall frostOctober 1150% chance of a frost before it
  • Frost-free season155 daystypical year, 32°F
  • Hardiness zone7acalculated*

The year at a glance

Frost season at New Harmony, UTSpring: a frost after April 23 in 9 years out of 10, after May 9 in half of the years, after May 29 in 1 year out of 10. Fall: the first frost comes before September 27 in 1 year out of 10, before October 11 in half of the years, before October 25 in 9 years out of 10. Typical frost-free season: 155 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 9First frost ~Oct 11Frost season at New Harmony, UTSpring: a frost after April 23 in 9 years out of 10, after May 9 in half of the years, after May 29 in 1 year out of 10. Fall: the first frost comes before September 27 in 1 year out of 10, before October 11 in half of the years, before October 25 in 9 years out of 10. Typical frost-free season: 155 days.JFMAMJJASONDLast frost ~May 9First frost ~Oct 11
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 29September 27
50% (typical)May 9October 11
90% (likely)April 23October 25
Frost-free season (32°F, 50% chance)
155 days
Hard frost (28°F), last in spring, 50% chance after
April 24
Hard frost (28°F), first in fall, 50% chance before
October 22

The last 15 years (2006–2020 normals)

Typical last frost May 7 (2 days earlier than the 30-year normal), typical first fall frost October 8 (3 days earlier). Frost-free season 153 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 Harmony: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 29, 20% May 22, 30% May 17, 40% May 14, 50% May 9, 60% May 4, 70% May 1, 80% April 28, 90% April 23. Observed last spring frost in recent years: 2021 May 22, 2022 April 30, 2023 May 6, 2024 May 10, 2025 April 20, 2026 May 19.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 29May 9Apr 232021: May 222022: April 302023: May 62024: May 102025: April 202026: May 19Fall at New Harmony: chance of a frost before this dateFall, chance of a frost before the date: 10% September 27, 20% October 1, 30% October 4, 40% October 7, 50% October 11, 60% October 14, 70% October 17, 80% October 20, 90% October 25. Observed first fall frost in recent years: 2021 October 12, 2022 October 23, 2023 October 13, 2024 October 25, 2025 October 16.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 27Oct 11Oct 252021: October 122022: October 232023: October 132024: October 252025: October 16
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 22October 12
2022April 30October 23
2023May 6October 13
2024May 10October 25
2025April 20October 16
2026May 19season not over yet

What these dates mean

May 29 is the cautious spring date for tender crops in New Harmony, allowing a gardener to set them out when there is only a 10% chance of a later light frost. By contrast, April 23 carries a 90% chance, making an early planting a gamble.

The 50% date is May 9, meaning a 50% chance of a light frost later than this date, and the 50% date is October 11, meaning a 50% chance of a light frost earlier than this date. September 27 is the cautious fall date to finish harvesting tender crops, with only a 10% chance that a light frost has already arrived. The hard-frost 50% dates are April 24 in spring and October 22 in fall; a hard frost at 28°F can injure plants that survive a 32°F light frost, so these dates are especially significant.

How to read the probabilities

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

  • Spring: "10% after May 29" 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 27" 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 Harmony, UTNumbered nearest stations: 1 — Zion National Park, UT — 24 mi; 2 — Alton, UT — 44 mi; 3 — Kanab, UT — 51 mi; 4 — Pipe Spring National Monument, AZ — 51 mi; 5 — Bryce Canyon National Park Headquarters, UT — 63 mi.UTNV25 mi · 40 km1. Zion National Park, UT — 24 mi12. Alton, UT — 44 mi23. Kanab, UT — 51 mi34. Pipe Spring National Monument, AZ — 51 mi45. Bryce Canyon National Park Headquarters, UT — 63 mi5
  1. Zion National Park, UT 24 mi (39 km)
  2. Alton, UT 44 mi (71 km)
  3. Kanab, UT 51 mi (82 km)
  4. Pipe Spring National Monument, AZ 51 mi (83 km)
  5. Bryce Canyon National Park Headquarters, UT 63 mi (101 km)

Sources

* Hardiness zone 7a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 37.4636, -113.2897.