U.S. Frost Dates by Weather Station

NOAA station USC00027619 · Arizona

Frost Dates for Sasabe, AZ

NOAA weather station Sasabe (USC00027619), Arizona · elevation 3590 ft (1094 m) · hardiness zone 9a*

  • Lower-risk planting dateafter April 14only 1 spring in 10 still has a frost later
  • Typical last frostMarch 2150% chance of a frost after it
  • Typical first fall frostNovember 2050% chance of a frost before it
  • Frost-free season246 daystypical year, 32°F
  • Hardiness zone9acalculated*

The year at a glance

Frost season at Sasabe, AZSpring: a frost after February 23 in 9 years out of 10, after March 21 in half of the years, after April 14 in 1 year out of 10. Fall: the first frost comes before November 1 in 1 year out of 10, before November 20 in half of the years, before December 7 in 9 years out of 10. Typical frost-free season: 246 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Mar 21First frost ~Nov 20Frost season at Sasabe, AZSpring: a frost after February 23 in 9 years out of 10, after March 21 in half of the years, after April 14 in 1 year out of 10. Fall: the first frost comes before November 1 in 1 year out of 10, before November 20 in half of the years, before December 7 in 9 years out of 10. Typical frost-free season: 246 days.JFMAMJJASONDLast frost ~Mar 21First frost ~Nov 20
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)April 14November 1
50% (typical)March 21November 20
90% (likely)February 23December 7
Frost-free season (32°F, 50% chance)
246 days
Hard frost (28°F), last in spring, 50% chance after
February 20
Hard frost (28°F), first in fall, 50% chance before
December 3

The last 15 years (2006–2020 normals)

Typical last frost March 19 (2 days earlier than the 30-year normal), typical first fall frost November 24 (4 days later). Frost-free season 247 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 Sasabe: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 14, 20% April 5, 30% March 31, 40% March 27, 50% March 21, 60% March 14, 70% March 7, 80% March 2, 90% February 23. Observed last spring frost in recent years: 2021 March 17, 2022 April 13, 2024 March 17, 2025 January 31, 2026 January 10.Spring: last frostChance of a frost after this date10%50%90%Feb 1Mar 1Apr 1Apr 14Mar 21Feb 232021: March 172022: April 132024: March 172025: January 312026: January 10Fall at Sasabe: chance of a frost before this dateFall, chance of a frost before the date: 10% November 1, 20% November 7, 30% November 13, 40% November 16, 50% November 20, 60% November 24, 70% November 28, 80% December 2, 90% December 7. Observed first fall frost in recent years: 2021 December 12, 2022 November 4, 2023 December 3, 2024 November 7, 2025 January 9.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Jan 1Nov 1Nov 20Dec 72021: December 122022: November 42023: December 32024: November 72025: January 9
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
2021March 17December 12
2022April 13November 4
2023incomplete recordDecember 3
2024March 17November 7
2025January 31January 9
2026January 10season not over yet

What these dates mean

April 14 is the cautious spring date, marking a 10% chance that a light frost will occur later; this lets a gardener set out tender crops with relatively low risk.

The 50% spring date is March 21, the point where a light frost has an even chance of happening later, and the 50% fall date is November 20, the point where a light frost has an even chance of happening earlier. The median hard-frost dates are February 20 in spring and December 3 in fall.

November 1 is the cautious fall date, with a 10% chance that a light frost has already arrived, allowing the gardener to finish harvesting tender crops. A hard frost at 28 °F can damage or kill plants that survive a 32 °F light frost, so it represents a greater risk.

How to read the probabilities

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

  • Spring: "10% after April 14" 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 November 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 Sasabe, AZNumbered nearest stations: 1 — near Tubac, AZ — 30 mi; 2 — near Sierra Vista Southeast, AZ — 77 mi; 3 — Benson, AZ — 81 mi; 4 — Tombstone, AZ — 88 mi; 5 — near Douglas, AZ — 114 mi.AZ25 mi · 40 km1. near Tubac, AZ — 30 mi12. near Sierra Vista Southeast, AZ — 77 mi23. Benson, AZ — 81 mi34. Tombstone, AZ — 88 mi45. near Douglas, AZ — 114 mi5
  1. near Tubac, AZ 30 mi (48 km)
  2. near Sierra Vista Southeast, AZ 77 mi (123 km)
  3. Benson, AZ 81 mi (131 km)
  4. Tombstone, AZ 88 mi (142 km)
  5. near Douglas, AZ 114 mi (184 km)

Sources

* Hardiness zone 9a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 31.4831, -111.5436.