U.S. Frost Dates by Weather Station

NOAA station USC00021248 · Arizona

Frost Dates for Canyon De Chelly, AZ

NOAA weather station Canyon De Chelly (USC00021248), Arizona · elevation 5610 ft (1710 m) · hardiness zone 7a*

  • Lower-risk planting dateafter May 31only 1 spring in 10 still has a frost later
  • Typical last frostMay 650% chance of a frost after it
  • Typical first fall frostOctober 850% chance of a frost before it
  • Frost-free season153 daystypical year, 32°F
  • Hardiness zone7acalculated*

The year at a glance

Frost season at Canyon De Chelly, AZSpring: a frost after April 22 in 9 years out of 10, after May 6 in half of the years, after May 31 in 1 year out of 10. Fall: the first frost comes before September 26 in 1 year out of 10, before October 8 in half of the years, before October 23 in 9 years out of 10. Typical frost-free season: 153 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 6First frost ~Oct 8Frost season at Canyon De Chelly, AZSpring: a frost after April 22 in 9 years out of 10, after May 6 in half of the years, after May 31 in 1 year out of 10. Fall: the first frost comes before September 26 in 1 year out of 10, before October 8 in half of the years, before October 23 in 9 years out of 10. Typical frost-free season: 153 days.JFMAMJJASONDLast frost ~May 6First frost ~Oct 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 28 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 31September 26
50% (typical)May 6October 8
90% (likely)April 22October 23
Frost-free season (32°F, 50% chance)
153 days
Hard frost (28°F), last in spring, 50% chance after
April 24
Hard frost (28°F), first in fall, 50% chance before
October 18

The last 15 years (2006–2020 normals)

Typical last frost May 7 (1 day later than the 30-year normal), typical first fall frost October 7 (1 day earlier). Frost-free season 154 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 Canyon De Chelly: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 31, 20% May 22, 30% May 15, 40% May 11, 50% May 6, 60% May 2, 70% April 30, 80% April 26, 90% April 22. Observed last spring frost in recent years: 2021 May 25, 2022 May 6, 2023 April 26, 2024 May 12, 2025 May 20, 2026 May 8.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 31May 6Apr 222021: May 252022: May 62023: April 262024: May 122025: May 202026: May 8Fall at Canyon De Chelly: chance of a frost before this dateFall, chance of a frost before the date: 10% September 26, 20% September 30, 30% October 3, 40% October 5, 50% October 8, 60% October 11, 70% October 15, 80% October 18, 90% October 23. Observed first fall frost in recent years: 2021 October 13, 2022 October 24, 2023 October 13, 2024 October 21.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 26Oct 8Oct 232021: October 132022: October 242023: October 132024: October 21
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 25October 13
2022May 6October 24
2023April 26October 13
2024May 12October 21
2025May 20incomplete record
2026May 8season not over yet

What these dates mean

Planting tender crops on April 22 in Canyon De Chelly is a gamble; the record shows a 90 % chance that a light frost will occur later that season. Gardeners who prefer a lower risk wait until the cautious date of May 31, when only a 10 % chance of a frost later remains.

The 50 % date of May 6 indicates a 50 % chance of a light frost later than this date, while the October 8 50 % date indicates a 50 % chance of a light frost earlier than this date. For a cautious fall schedule, the low-risk date is September 26, with just a 10 % chance that a frost has arrived earlier. Hard-frost thresholds are lower; a 28 °F event on April 24 or October 18 can damage plants that survive the 32 °F light frosts.

How to read the probabilities

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

  • Spring: "10% after May 31" 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 26" 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 Canyon De Chelly, AZNumbered nearest stations: 1 — Betatakin, AZ — 66 mi; 2 — Farmington, NM — 78 mi; 3 — Bluff, UT — 78 mi; 4 — Zuni, NM — 85 mi; 5 — Petrified Forest National Park, AZ — 96 mi.AZNMUTCO50 mi · 80 km1. Betatakin, AZ — 66 mi12. Farmington, NM — 78 mi23. Bluff, UT — 78 mi34. Zuni, NM — 85 mi45. Petrified Forest National Park, AZ — 96 mi5
  1. Betatakin, AZ 66 mi (107 km)
  2. Farmington, NM 78 mi (125 km)
  3. Bluff, UT 78 mi (126 km)
  4. Zuni, NM 85 mi (136 km)
  5. Petrified Forest National Park, AZ 96 mi (154 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: 36.1533, -109.5394.