U.S. Frost Dates by Weather Station

NOAA station USC00427729 · Utah

Frost Dates for Scofield-Skyline Mine, UT

NOAA weather station Scofield-Skyline Mine (USC00427729), Utah · elevation 8697 ft (2651 m) · hardiness zone 5b*

  • Lower-risk planting dateafter June 30only 1 spring in 10 still has a frost later
  • Typical last frostJune 1350% chance of a frost after it
  • Typical first fall frostSeptember 1750% chance of a frost before it
  • Frost-free season94 daystypical year, 32°F
  • Hardiness zone5bcalculated*

The year at a glance

Frost season at Scofield-Skyline Mine, UTSpring: a frost after May 29 in 9 years out of 10, after June 13 in half of the years, after June 30 in 1 year out of 10. Fall: the first frost comes before September 1 in 1 year out of 10, before September 17 in half of the years, before September 28 in 9 years out of 10. Typical frost-free season: 94 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Jun 13First frost ~Sep 17Frost season at Scofield-Skyline Mine, UTSpring: a frost after May 29 in 9 years out of 10, after June 13 in half of the years, after June 30 in 1 year out of 10. Fall: the first frost comes before September 1 in 1 year out of 10, before September 17 in half of the years, before September 28 in 9 years out of 10. Typical frost-free season: 94 days.JFMAMJJASONDLast frost ~Jun 13First frost ~Sep 17
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)June 30September 1
50% (typical)June 13September 17
90% (likely)May 29September 28
Frost-free season (32°F, 50% chance)
94 days
Hard frost (28°F), last in spring, 50% chance after
June 1
Hard frost (28°F), first in fall, 50% chance before
September 26

The last 15 years (2006–2020 normals)

Typical last frost June 9 (4 days earlier than the 30-year normal), typical first fall frost September 21 (4 days later). Frost-free season 102 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 Scofield-Skyline Mine: chance of a frost after this dateSpring, chance of a frost after the date: 10% June 30, 20% June 24, 30% June 21, 40% June 17, 50% June 13, 60% June 10, 70% June 6, 80% June 3, 90% May 29. Observed last spring frost in recent years: 2021 June 12, 2022 June 21, 2023 May 18, 2024 June 18, 2025 May 24, 2026 June 29.Spring: last frostChance of a frost after this date10%50%90%Jun 1Jul 1Jun 30Jun 13May 292021: June 122022: June 212023: May 182024: June 182025: May 242026: June 29Fall at Scofield-Skyline Mine: chance of a frost before this dateFall, chance of a frost before the date: 10% September 1, 20% September 7, 30% September 11, 40% September 15, 50% September 17, 60% September 20, 70% September 23, 80% September 25, 90% September 28. Observed first fall frost in recent years: 2021 September 19, 2022 September 22, 2023 September 23, 2024 September 13, 2025 September 23.Fall: first frostChance of a frost before this date10%50%90%Sep 1Oct 1Sep 1Sep 17Sep 282021: September 192022: September 222023: September 232024: September 132025: September 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
2021June 12September 19
2022June 21September 22
2023May 18September 23
2024June 18September 13
2025May 24September 23
2026June 29season not over yet

What these dates mean

Setting out tender crops on the early spring date, May 29, is a gamble at Scofield-Skyline Mine because there is a 90% chance of a light frost later that season. By contrast, the late spring date, June 30, carries only a 10% chance and is the cautious choice for planting.

The 50% dates are June 13 in spring and September 17 in fall; they represent a 50% chance of a light frost later than June 13 and a 50% chance of a light frost earlier than September 17. Gardeners can use these points to gauge when the probability of frost is evenly balanced.

For finishing tender crops, September 1 is the cautious fall date with a 10% chance of an early frost, while September 28 is a gamble with a 90% chance. A hard frost, defined by 28°F, is noted on June 1 and September 26, and it poses a greater threat to plant tissue 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 June 30" 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 1" 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 Scofield-Skyline Mine, UTNumbered nearest stations: 1 — Ephraim, UT — 31 mi; 2 — Nephi, UT — 33 mi; 3 — Spanish Fork, UT — 35 mi; 4 — near Santaquin, UT — 36 mi; 5 — Manti, UT — 37 mi.UT25 mi · 40 km1. Ephraim, UT — 31 mi12. Nephi, UT — 33 mi23. Spanish Fork, UT — 35 mi34. near Santaquin, UT — 36 mi45. Manti, UT — 37 mi5
  1. Ephraim, UT 31 mi (50 km)
  2. Nephi, UT 33 mi (54 km)
  3. Spanish Fork, UT 35 mi (56 km)
  4. near Santaquin, UT 36 mi (58 km)
  5. Manti, UT 37 mi (60 km)

Sources

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

Station coordinates: 39.6842, -111.2056.