U.S. Frost Dates by Weather Station

NOAA station USW00094224 · Oregon

Frost Dates for Astoria, OR

NOAA weather station Astoria Regional Airport (USW00094224), Oregon · elevation 9 ft (3 m) · hardiness zone 9a*

  • Lower-risk planting dateafter April 18only 1 spring in 10 still has a frost later
  • Typical last frostMarch 2650% chance of a frost after it
  • Typical first fall frostNovember 1150% chance of a frost before it
  • Frost-free season232 daystypical year, 32°F
  • Hardiness zone9acalculated*

The year at a glance

Frost season at Astoria, ORSpring: a frost after February 27 in 9 years out of 10, after March 26 in half of the years, after April 18 in 1 year out of 10. Fall: the first frost comes before October 22 in 1 year out of 10, before November 11 in half of the years, before December 8 in 9 years out of 10. Typical frost-free season: 232 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Mar 26First frost ~Nov 11Frost season at Astoria, ORSpring: a frost after February 27 in 9 years out of 10, after March 26 in half of the years, after April 18 in 1 year out of 10. Fall: the first frost comes before October 22 in 1 year out of 10, before November 11 in half of the years, before December 8 in 9 years out of 10. Typical frost-free season: 232 days.JFMAMJJASONDLast frost ~Mar 26First frost ~Nov 11
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)April 18October 22
50% (typical)March 26November 11
90% (likely)February 27December 8
Frost-free season (32°F, 50% chance)
232 days
Hard frost (28°F), last in spring, 50% chance after
February 18
Hard frost (28°F), first in fall, 50% chance before
December 5

The last 15 years (2006–2020 normals)

Typical last frost March 26 (same as the 30-year normal), typical first fall frost November 12 (1 day later). Frost-free season 231 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 Astoria: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 18, 20% April 9, 30% April 3, 40% March 29, 50% March 26, 60% March 20, 70% March 14, 80% March 7, 90% February 27. Observed last spring frost in recent years: 2021 April 11, 2022 March 31, 2023 April 5, 2024 March 7, 2025 April 13, 2026 March 30.Spring: last frostChance of a frost after this date10%50%90%Mar 1Apr 1May 1Apr 18Mar 26Feb 272021: April 112022: March 312023: April 52024: March 72025: April 132026: March 30Fall at Astoria: chance of a frost before this dateFall, chance of a frost before the date: 10% October 22, 20% October 29, 30% November 2, 40% November 6, 50% November 11, 60% November 16, 70% November 22, 80% November 29, 90% December 8. Observed first fall frost in recent years: 2021 November 21, 2022 November 9, 2023 October 29, 2024 November 28, 2025 December 26.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Jan 1Oct 22Nov 11Dec 82021: November 212022: November 92023: October 292024: November 282025: December 26
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 11November 21
2022March 31November 9
2023April 5October 29
2024March 7November 28
2025April 13December 26
2026March 30season not over yet

What these dates mean

October 22 marks the cautious fall date in Astoria for finishing the harvest, when there is only a 10% chance that a light frost has already arrived. Gardeners who wait until April 18 to set out tender crops in spring are using the cautious date, which carries a 10% chance of a frost later than that day.

The 50% date is March 26; there is a 50% chance of a frost later than this date, and the 50% date is November 11; there is a 50% chance of a frost earlier than this date. These median dates define the point at which frost risk is even.

A hard frost (28 °F), whose 50% dates are February 18 and December 5, is more damaging than a light frost (32 °F) because the lower temperature can freeze plant tissue.

How to read the probabilities

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

  • Spring: "10% after April 18" 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 22" 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 Astoria, ORNumbered nearest stations: 1 — Long Beach, WA — 16 mi; 2 — Clatskanie, OR — 33 mi; 3 — Raymond, WA — 35 mi; 4 — near Vernonia, OR — 39 mi; 5 — Longview, WA — 46 mi.WA25 mi · 40 km1. Long Beach, WA — 16 mi12. Clatskanie, OR — 33 mi23. Raymond, WA — 35 mi34. near Vernonia, OR — 39 mi45. Longview, WA — 46 mi5
  1. Long Beach, WA 16 mi (26 km)
  2. Clatskanie, OR 33 mi (52 km)
  3. Raymond, WA 35 mi (56 km)
  4. near Vernonia, OR 39 mi (63 km)
  5. Longview, WA 46 mi (74 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: 46.1569, -123.8825.