U.S. Frost Dates by Weather Station

NOAA station USW00024243 · Washington

Frost Dates for Yakima, WA

NOAA weather station Yakima Air Terminal (USW00024243), Washington · elevation 1064 ft (324 m) · hardiness zone 7a*

  • Lower-risk planting dateafter May 27only 1 spring in 10 still has a frost later
  • Typical last frostMay 850% chance of a frost after it
  • Typical first fall frostOctober 450% chance of a frost before it
  • Frost-free season149 daystypical year, 32°F
  • Hardiness zone7acalculated*

The year at a glance

Frost season at Yakima, WASpring: a frost after April 24 in 9 years out of 10, after May 8 in half of the years, after May 27 in 1 year out of 10. Fall: the first frost comes before September 23 in 1 year out of 10, before October 4 in half of the years, before October 17 in 9 years out of 10. Typical frost-free season: 149 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 8First frost ~Oct 4Frost season at Yakima, WASpring: a frost after April 24 in 9 years out of 10, after May 8 in half of the years, after May 27 in 1 year out of 10. Fall: the first frost comes before September 23 in 1 year out of 10, before October 4 in half of the years, before October 17 in 9 years out of 10. Typical frost-free season: 149 days.JFMAMJJASONDLast frost ~May 8First frost ~Oct 4
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 30 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 27September 23
50% (typical)May 8October 4
90% (likely)April 24October 17
Frost-free season (32°F, 50% chance)
149 days
Hard frost (28°F), last in spring, 50% chance after
April 23
Hard frost (28°F), first in fall, 50% chance before
October 16

The last 15 years (2006–2020 normals)

Typical last frost May 5 (3 days earlier than the 30-year normal), typical first fall frost October 5 (1 day later). Frost-free season 151 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 Yakima: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 27, 20% May 20, 30% May 15, 40% May 10, 50% May 8, 60% May 4, 70% April 30, 80% April 28, 90% April 24. Observed last spring frost in recent years: 2021 April 26, 2022 May 11, 2023 April 25, 2024 May 7, 2025 May 5, 2026 April 27.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 27May 8Apr 242021: April 262022: May 112023: April 252024: May 72025: May 52026: April 27Fall at Yakima: chance of a frost before this dateFall, chance of a frost before the date: 10% September 23, 20% September 27, 30% September 30, 40% October 2, 50% October 4, 60% October 6, 70% October 9, 80% October 13, 90% October 17. Observed first fall frost in recent years: 2021 October 7, 2022 October 23, 2023 October 25, 2024 October 1, 2025 October 14.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 23Oct 4Oct 172021: October 72022: October 232023: October 252024: October 12025: October 14
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
2021April 26October 7
2022May 11October 23
2023April 25October 25
2024May 7October 1
2025May 5October 14
2026April 27season not over yet

What these dates mean

May 27 in Yakima carries only a 10 % chance of a light frost later, making it the cautious spring date for setting out tender crops. The 50 % light-frost date is May 8, which marks an even chance of a frost later, while the 50 % hard-frost date is April 23. Gardeners can use these three points to gauge risk as the season progresses.

In autumn, September 23 holds a 10 % chance of a light frost earlier, so it is the cautious date to finish harvesting tender crops. The 50 % light-frost date is October 4, and the 50 % hard-frost date is October 16. The interval between the two 32 °F 50 % dates spans 149 days, giving a sense of the frost-free window.

Hard frost matters more than light frost because temperatures of 28 °F can cause deeper damage to plant tissue than the milder 32 °F threshold.

How to read the probabilities

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

  • Spring: "10% after May 27" 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 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 Yakima, WANumbered nearest stations: 1 — Packwood, WA — 54 mi; 2 — Wenatchee (Pangborn Airport), WA — 60 mi; 3 — Wenatchee, WA — 60 mi; 4 — Richland, WA — 63 mi; 5 — Boardman, OR — 64 mi.OR50 mi · 80 km1. Packwood, WA — 54 mi12. Wenatchee (Pangborn Airport), WA — 60 mi23. Wenatchee, WA — 60 mi34. Richland, WA — 63 mi45. Boardman, OR — 64 mi5
  1. Packwood, WA 54 mi (87 km)
  2. Wenatchee (Pangborn Airport), WA 60 mi (96 km)
  3. Wenatchee, WA 60 mi (97 km)
  4. Richland, WA 63 mi (102 km)
  5. Boardman, OR 64 mi (103 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: 46.5683, -120.5428.