U.S. Frost Dates by Weather Station

NOAA station USC00450008 · Washington

Frost Dates for Aberdeen, WA

NOAA weather station Aberdeen (USC00450008), Washington · elevation 10 ft (3 m) · hardiness zone 9a*

  • Lower-risk planting dateafter April 20only 1 spring in 10 still has a frost later
  • Typical last frostMarch 2950% chance of a frost after it
  • Typical first fall frostNovember 1550% chance of a frost before it
  • Frost-free season234 daystypical year, 32°F
  • Hardiness zone9acalculated*

The year at a glance

Frost season at Aberdeen, WASpring: a frost after February 25 in 9 years out of 10, after March 29 in half of the years, after April 20 in 1 year out of 10. Fall: the first frost comes before October 27 in 1 year out of 10, before November 15 in half of the years, before December 10 in 9 years out of 10. Typical frost-free season: 234 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Mar 29First frost ~Nov 15Frost season at Aberdeen, WASpring: a frost after February 25 in 9 years out of 10, after March 29 in half of the years, after April 20 in 1 year out of 10. Fall: the first frost comes before October 27 in 1 year out of 10, before November 15 in half of the years, before December 10 in 9 years out of 10. Typical frost-free season: 234 days.JFMAMJJASONDLast frost ~Mar 29First frost ~Nov 15
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)April 20October 27
50% (typical)March 29November 15
90% (likely)February 25December 10
Frost-free season (32°F, 50% chance)
234 days
Hard frost (28°F), last in spring, 50% chance after
February 18
Hard frost (28°F), first in fall, 50% chance before
December 6

The last 15 years (2006–2020 normals)

Typical last frost March 27 (2 days earlier than the 30-year normal), typical first fall frost November 15. Frost-free season 233 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 Aberdeen: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 20, 20% April 12, 30% April 5, 40% April 1, 50% March 29, 60% March 23, 70% March 15, 80% March 6, 90% February 25. Observed last spring frost in recent years: 2021 April 12.Spring: last frostChance of a frost after this date10%50%90%Mar 1Apr 1May 1Apr 20Mar 29Feb 252021: April 12Fall at Aberdeen: chance of a frost before this dateFall, chance of a frost before the date: 10% October 27, 20% November 1, 30% November 6, 40% November 11, 50% November 15, 60% November 21, 70% November 26, 80% December 1, 90% December 10. Observed first fall frost in recent years: 2021 November 22.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Oct 27Nov 15Dec 102021: November 22
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 12November 22
2022incomplete recordno data
2023no datano data
2024no datano data
2025no datano data
2026no dataseason not over yet

What these dates mean

April 20 is the cautious spring date for Aberdeen; with only a 10 % chance of a light frost later, a gardener can plan to set out tender crops after that day.

The 50 % spring date, March 29, marks the median point where a frost is equally likely to occur later, while the 50 % fall date, November 15, is the median when a frost is equally likely to have arrived earlier. October 27 is the cautious fall date, carrying just a 10 % chance that a light frost has already arrived, so it is the latest day to finish harvesting tender crops. The 50 % hard-frost dates are February 18 in spring and December 6 in fall; a hard frost at 28 °F can injure plants more severely than a light frost at 32 °F, making those dates especially relevant for protecting vulnerable growth.

How to read the probabilities

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

  • Spring: "10% after April 20" 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 27" 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 Aberdeen, WANumbered nearest stations: 1 — near Hoquiam, WA — 5 mi; 2 — Humptulips Salmon Hatchery, WA — 20 mi; 3 — Elma, WA — 20 mi; 4 — Raymond, WA — 22 mi; 5 — Cushman Powerhouse #2, WA — 42 mi.WA25 mi · 40 km1. near Hoquiam, WA — 5 mi12. Humptulips Salmon Hatchery, WA — 20 mi23. Elma, WA — 20 mi34. Raymond, WA — 22 mi45. Cushman Powerhouse #2, WA — 42 mi5
  1. near Hoquiam, WA 5 mi (8 km)
  2. Humptulips Salmon Hatchery, WA 20 mi (32 km)
  3. Elma, WA 20 mi (33 km)
  4. Raymond, WA 22 mi (36 km)
  5. Cushman Powerhouse #2, WA 42 mi (68 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: 46.9658, -123.8292.