U.S. Frost Dates by Weather Station

NOAA station USC00421008 · Utah

Frost Dates for Bryce Canyon National Park Headquarters, UT

NOAA weather station Bryce Canyon National Park Headquarters (USC00421008), Utah · elevation 7890 ft (2405 m) · hardiness zone 5b*

  • Lower-risk planting dateafter June 9only 1 spring in 10 still has a frost later
  • Typical last frostMay 2350% chance of a frost after it
  • Typical first fall frostSeptember 2750% chance of a frost before it
  • Frost-free season125 daystypical year, 32°F
  • Hardiness zone5bcalculated*

The year at a glance

Frost season at Bryce Canyon National Park Headquarters, UTSpring: a frost after May 8 in 9 years out of 10, after May 23 in half of the years, after June 9 in 1 year out of 10. Fall: the first frost comes before September 13 in 1 year out of 10, before September 27 in half of the years, before October 11 in 9 years out of 10. Typical frost-free season: 125 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 23First frost ~Sep 27Frost season at Bryce Canyon National Park Headquarters, UTSpring: a frost after May 8 in 9 years out of 10, after May 23 in half of the years, after June 9 in 1 year out of 10. Fall: the first frost comes before September 13 in 1 year out of 10, before September 27 in half of the years, before October 11 in 9 years out of 10. Typical frost-free season: 125 days.JFMAMJJASONDLast frost ~May 23First frost ~Sep 27
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 26 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)June 9September 13
50% (typical)May 23September 27
90% (likely)May 8October 11
Frost-free season (32°F, 50% chance)
125 days
Hard frost (28°F), last in spring, 50% chance after
May 7
Hard frost (28°F), first in fall, 50% chance before
October 8

The last 15 years (2006–2020 normals)

Typical last frost May 27 (4 days later than the 30-year normal), typical first fall frost September 27. Frost-free season 123 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 Bryce Canyon National Park Headquarters: chance of a frost after this dateSpring, chance of a frost after the date: 10% June 9, 20% June 2, 30% May 31, 40% May 27, 50% May 23, 60% May 20, 70% May 17, 80% May 13, 90% May 8. Observed last spring frost in recent years: 2021 June 11, 2022 June 21, 2023 June 26, 2024 June 20, 2025 June 26, 2026 May 30.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1Jul 1Jun 9May 23May 82021: June 112022: June 212023: June 262024: June 202025: June 262026: May 30Fall at Bryce Canyon National Park Headquarters: chance of a frost before this dateFall, chance of a frost before the date: 10% September 13, 20% September 19, 30% September 22, 40% September 25, 50% September 27, 60% September 29, 70% October 1, 80% October 5, 90% October 11. Observed first fall frost in recent years: 2021 September 21, 2022 September 24, 2023 September 22, 2024 September 13, 2025 September 24.Fall: first frostChance of a frost before this date10%50%90%Sep 1Oct 1Sep 13Sep 27Oct 112021: September 212022: September 242023: September 222024: September 132025: September 24
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 11September 21
2022June 21September 24
2023June 26September 22
2024June 20September 13
2025June 26September 24
2026May 30season not over yet

What these dates mean

Setting out tender crops on the early spring date, May 8, carries a 90 % chance of a frost later than that date, making it a gamble for growers at Bryce Canyon National Park Headquarters. The cautious approach in spring waits until the June 9 date, which has only a 10 % chance of a later frost.

The 50% date is May 23, meaning there is an even odds chance of a frost later than this date in spring, while the 50% date is September 27, giving an even odds chance of a frost earlier than this date in fall. To finish harvesting tender crops with minimal risk, the fall cautious date is September 13, which has a 10 % chance of an earlier frost. In contrast, counting on tender crops as late as October 11 is a gamble with a 90 % chance of an earlier frost.

Hard frost at 28 °F, marked by the median dates May 7 and October 8, matters more than light frost because it can damage plants that survive a 32 °F frost.

How to read the probabilities

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

  • Spring: "10% after June 9" 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 13" 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 Bryce Canyon National Park Headquarters, UTNumbered nearest stations: 1 — Alton, UT — 22 mi; 2 — Escalante, UT — 33 mi; 3 — Boulder, UT — 45 mi; 4 — Kanab, UT — 47 mi; 5 — Zion National Park, UT — 54 mi.UTAZ25 mi · 40 km1. Alton, UT — 22 mi12. Escalante, UT — 33 mi23. Boulder, UT — 45 mi34. Kanab, UT — 47 mi45. Zion National Park, UT — 54 mi5
  1. Alton, UT 22 mi (35 km)
  2. Escalante, UT 33 mi (52 km)
  3. Boulder, UT 45 mi (72 km)
  4. Kanab, UT 47 mi (75 km)
  5. Zion National Park, UT 54 mi (86 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: 37.6411, -112.1703.