U.S. Frost Dates by Weather Station

NOAA station USC00422798 · Utah

Frost Dates for Ferron, UT

NOAA weather station Ferron (USC00422798), Utah · elevation 5923 ft (1805 m) · hardiness zone 6b*

  • Lower-risk planting dateafter May 27only 1 spring in 10 still has a frost later
  • Typical last frostMay 650% chance of a frost after it
  • Typical first fall frostOctober 1050% chance of a frost before it
  • Frost-free season156 daystypical year, 32°F
  • Hardiness zone6bcalculated*

The year at a glance

Frost season at Ferron, UTSpring: a frost after April 22 in 9 years out of 10, after May 6 in half of the years, after May 27 in 1 year out of 10. Fall: the first frost comes before September 28 in 1 year out of 10, before October 10 in half of the years, before October 22 in 9 years out of 10. Typical frost-free season: 156 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 6First frost ~Oct 10Frost season at Ferron, UTSpring: a frost after April 22 in 9 years out of 10, after May 6 in half of the years, after May 27 in 1 year out of 10. Fall: the first frost comes before September 28 in 1 year out of 10, before October 10 in half of the years, before October 22 in 9 years out of 10. Typical frost-free season: 156 days.JFMAMJJASONDLast frost ~May 6First frost ~Oct 10
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 28 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 27September 28
50% (typical)May 6October 10
90% (likely)April 22October 22
Frost-free season (32°F, 50% chance)
156 days
Hard frost (28°F), last in spring, 50% chance after
April 23
Hard frost (28°F), first in fall, 50% chance before
October 19

The last 15 years (2006–2020 normals)

Typical last frost May 5 (1 day earlier than the 30-year normal), typical first fall frost October 10. Frost-free season 157 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 Ferron: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 27, 20% May 19, 30% May 14, 40% May 10, 50% May 6, 60% May 2, 70% April 30, 80% April 26, 90% April 22. Observed last spring frost in recent years: 2022 May 23, 2024 May 24, 2025 May 20, 2026 May 19.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 27May 6Apr 222022: May 232024: May 242025: May 202026: May 19Fall at Ferron: chance of a frost before this dateFall, chance of a frost before the date: 10% September 28, 20% October 1, 30% October 5, 40% October 7, 50% October 10, 60% October 13, 70% October 15, 80% October 18, 90% October 22. Observed first fall frost in recent years: 2022 October 24, 2023 October 16, 2024 October 31, 2025 October 17.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 28Oct 10Oct 222022: October 242023: October 162024: October 312025: October 17
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
2021incomplete recordincomplete record
2022May 23October 24
2023incomplete recordOctober 16
2024May 24October 31
2025May 20October 17
2026May 19season not over yet

What these dates mean

The 156 days between the 50% dates in Ferron, May 6 and October 10, mark the median period during which a light frost (32 °F) is equally likely to have occurred or not. Within that span, gardeners gauge risk for tender crops.

For a cautious spring schedule, the station’s LATE light-frost date of May 27 carries only a 10 % chance of a frost later, making it the recommended day to set out tender crops, while the EARLY light-frost date of September 28 in fall carries a 10 % chance of a frost earlier, signalling the prudent time to finish harvesting tender crops. By contrast, planting on April 22 or keeping crops until October 22 involves a 90 % chance of frost and is a gamble.

Hard frost at 28 °F, with median dates of April 23 and October 19, matters more because temperatures that low can kill plant tissue that would survive a 32 °F 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 27" 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 28" 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 Ferron, UTNumbered nearest stations: 1 — Salina, UT — 19 mi; 2 — Manti, UT — 29 mi; 3 — Ephraim, UT — 31 mi; 4 — Scofield-Skyline Mine, UT — 41 mi; 5 — Capitol Reef National Park, UT — 55 mi.25 mi · 40 km1. Salina, UT — 19 mi12. Manti, UT — 29 mi23. Ephraim, UT — 31 mi34. Scofield-Skyline Mine, UT — 41 mi45. Capitol Reef National Park, UT — 55 mi5
  1. Salina, UT 19 mi (31 km)
  2. Manti, UT 29 mi (47 km)
  3. Ephraim, UT 31 mi (50 km)
  4. Scofield-Skyline Mine, UT 41 mi (67 km)
  5. Capitol Reef National Park, UT 55 mi (89 km)

Sources

* Hardiness zone 6b: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 39.0875, -111.1325.