U.S. Frost Dates by Weather Station

NOAA station USC00424174 · Utah

Frost Dates for Ibapah, UT

NOAA weather station Ibapah (USC00424174), Utah · elevation 5279 ft (1609 m) · hardiness zone 5b*

  • Lower-risk planting dateafter July 1only 1 spring in 10 still has a frost later
  • Typical last frostJune 1450% chance of a frost after it
  • Typical first fall frostSeptember 850% chance of a frost before it
  • Frost-free season86 daystypical year, 32°F
  • Hardiness zone5bcalculated*

The year at a glance

Frost season at Ibapah, UTSpring: a frost after May 23 in 9 years out of 10, after June 14 in half of the years, after July 1 in 1 year out of 10. Fall: the first frost comes before August 23 in 1 year out of 10, before September 8 in half of the years, before September 22 in 9 years out of 10. Typical frost-free season: 86 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Jun 14First frost ~Sep 8Frost season at Ibapah, UTSpring: a frost after May 23 in 9 years out of 10, after June 14 in half of the years, after July 1 in 1 year out of 10. Fall: the first frost comes before August 23 in 1 year out of 10, before September 8 in half of the years, before September 22 in 9 years out of 10. Typical frost-free season: 86 days.JFMAMJJASONDLast frost ~Jun 14First frost ~Sep 8
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)July 1August 23
50% (typical)June 14September 8
90% (likely)May 23September 22
Frost-free season (32°F, 50% chance)
86 days
Hard frost (28°F), last in spring, 50% chance after
May 25
Hard frost (28°F), first in fall, 50% chance before
September 19

The last 15 years (2006–2020 normals)

Typical last frost June 8 (6 days earlier than the 30-year normal), typical first fall frost September 11 (3 days later). Frost-free season 93 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 Ibapah: chance of a frost after this dateSpring, chance of a frost after the date: 10% July 1, 20% June 25, 30% June 21, 40% June 17, 50% June 14, 60% June 9, 70% June 5, 80% May 31, 90% May 23. Observed last spring frost in recent years: 2021 May 31, 2022 June 21, 2023 May 12, 2024 June 19, 2025 June 22, 2026 June 29.Spring: last frostChance of a frost after this date10%50%90%Jun 1Jul 1Jul 1Jun 14May 232021: May 312022: June 212023: May 122024: June 192025: June 222026: June 29Fall at Ibapah: chance of a frost before this dateFall, chance of a frost before the date: 10% August 23, 20% August 30, 30% September 3, 40% September 6, 50% September 8, 60% September 12, 70% September 15, 80% September 18, 90% September 22. Observed first fall frost in recent years: 2021 August 20, 2022 September 9, 2023 September 22, 2024 August 15, 2025 September 12.Fall: first frostChance of a frost before this date10%50%90%Sep 1Oct 1Aug 23Sep 8Sep 222021: August 202022: September 92023: September 222024: August 152025: September 12
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 31August 20
2022June 21September 9
2023May 12September 22
2024June 19August 15
2025June 22September 12
2026June 29season not over yet

What these dates mean

July 1 is the cautious spring date in Ibapah, giving a gardener a point at which only a 10 % chance remains that a light frost will occur later, so tender crops can be set out with relatively low risk. The cautious fall date is August 23, when there is only a 10 % chance that a light frost has already arrived, allowing the final harvest of tender crops.

The 50% spring date is June 14 and the 50% fall date is September 8; each marks the median point where the odds of a light frost later (spring) or earlier (fall) are equal. The 50% hard-frost dates are May 25 for spring and September 19 for fall, indicating the midpoint of risk for temperatures of 28 °F. A hard frost at 28 °F can cause more severe damage 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 July 1" 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 August 23" 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 Ibapah, UTNumbered nearest stations: 1 — Callao, UT — 17 mi; 2 — Partoun, UT — 29 mi; 3 — Lages, NV — 33 mi; 4 — Wendover, UT — 47 mi; 5 — McGill, NV — 60 mi.NVUT25 mi · 40 km1. Callao, UT — 17 mi12. Partoun, UT — 29 mi23. Lages, NV — 33 mi34. Wendover, UT — 47 mi45. McGill, NV — 60 mi5
  1. Callao, UT 17 mi (28 km)
  2. Partoun, UT 29 mi (46 km)
  3. Lages, NV 33 mi (53 km)
  4. Wendover, UT 47 mi (76 km)
  5. McGill, NV 60 mi (97 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: 40.0378, -113.9886.