U.S. Frost Dates by Weather Station

NOAA station USW00023194 · Arizona

Frost Dates for Winslow, AZ

NOAA weather station Winslow Municipal Airport (USW00023194), Arizona · elevation 4886 ft (1489 m) · hardiness zone 7a*

  • Lower-risk planting dateafter May 14only 1 spring in 10 still has a frost later
  • Typical last frostApril 2750% chance of a frost after it
  • Typical first fall frostOctober 1850% chance of a frost before it
  • Frost-free season174 daystypical year, 32°F
  • Hardiness zone7acalculated*

The year at a glance

Frost season at Winslow, AZSpring: a frost after April 12 in 9 years out of 10, after April 27 in half of the years, after May 14 in 1 year out of 10. Fall: the first frost comes before October 5 in 1 year out of 10, before October 18 in half of the years, before November 1 in 9 years out of 10. Typical frost-free season: 174 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 27First frost ~Oct 18Frost season at Winslow, AZSpring: a frost after April 12 in 9 years out of 10, after April 27 in half of the years, after May 14 in 1 year out of 10. Fall: the first frost comes before October 5 in 1 year out of 10, before October 18 in half of the years, before November 1 in 9 years out of 10. Typical frost-free season: 174 days.JFMAMJJASONDLast frost ~Apr 27First frost ~Oct 18
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 29 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 14October 5
50% (typical)April 27October 18
90% (likely)April 12November 1
Frost-free season (32°F, 50% chance)
174 days
Hard frost (28°F), last in spring, 50% chance after
April 13
Hard frost (28°F), first in fall, 50% chance before
October 27

The last 15 years (2006–2020 normals)

Typical last frost April 30 (3 days later than the 30-year normal), typical first fall frost October 19 (1 day later). Frost-free season 172 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 Winslow: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 14, 20% May 7, 30% May 3, 40% April 30, 50% April 27, 60% April 24, 70% April 21, 80% April 18, 90% April 12. Observed last spring frost in recent years: 2021 May 23, 2022 May 12, 2023 April 21, 2024 April 7, 2025 April 28, 2026 April 19.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 14Apr 27Apr 122021: May 232022: May 122023: April 212024: April 72025: April 282026: April 19Fall at Winslow: chance of a frost before this dateFall, chance of a frost before the date: 10% October 5, 20% October 10, 30% October 13, 40% October 16, 50% October 18, 60% October 21, 70% October 23, 80% October 27, 90% November 1. Observed first fall frost in recent years: 2021 October 13, 2022 October 25, 2023 October 13, 2024 October 31, 2025 October 29.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 5Oct 18Nov 12021: October 132022: October 252023: October 132024: October 312025: October 29
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 23October 13
2022May 12October 25
2023April 21October 13
2024April 7October 31
2025April 28October 29
2026April 19season not over yet

What these dates mean

Planting tender crops on the early spring date, April 12, is a gamble in Winslow because there is a 90 % chance of a light frost later than that date. Gardeners who wait until the cautious spring date, May 14, face only a 10 % chance of a frost after planting.

The 50% date is April 27, a 50 % chance of a light frost later than this date, while the 50% date is October 18, a 50 % chance of a light frost earlier than this date. The cautious fall date, October 5, carries a 10 % chance of a frost earlier than this date. The hard-frost 50% dates are April 13 and October 27, each marking an even chance of a hard frost. A hard frost at 28 °F can damage plant tissue that survives 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 May 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 October 5" 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 Winslow, AZNumbered nearest stations: 1 — Petrified Forest National Park, AZ — 50 mi; 2 — Wupatki National Monument, AZ — 50 mi; 3 — near Flagstaff, AZ — 54 mi; 4 — Payson, AZ — 65 mi; 5 — Show Low, AZ — 67 mi.AZ25 mi · 40 km1. Petrified Forest National Park, AZ — 50 mi12. Wupatki National Monument, AZ — 50 mi23. near Flagstaff, AZ — 54 mi34. Payson, AZ — 65 mi45. Show Low, AZ — 67 mi5
  1. Petrified Forest National Park, AZ 50 mi (80 km)
  2. Wupatki National Monument, AZ 50 mi (81 km)
  3. near Flagstaff, AZ 54 mi (87 km)
  4. Payson, AZ 65 mi (105 km)
  5. Show Low, AZ 67 mi (107 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: 35.0281, -110.7208.