U.S. Frost Dates by Weather Station

NOAA station USC00350897 · Oregon

Frost Dates near Cascade Locks, OR

NOAA weather station Bonneville Dam (USC00350897), Oregon · elevation 62 ft (19 m) · hardiness zone 8b*

Cascade Locks is the nearest town to the station (3.8 mi away) in GeoNames (CC BY 4.0). The dates below are measured at the station, not in the town itself.

  • Lower-risk planting dateafter April 4only 1 spring in 10 still has a frost later
  • Typical last frostMarch 1450% chance of a frost after it
  • Typical first fall frostNovember 2750% chance of a frost before it
  • Frost-free season257 daystypical year, 32°F
  • Hardiness zone8bcalculated*

The year at a glance

Frost season near Cascade Locks, ORSpring: a frost after February 19 in 9 years out of 10, after March 14 in half of the years, after April 4 in 1 year out of 10. Fall: the first frost comes before November 8 in 1 year out of 10, before November 27 in half of the years, before December 15 in 9 years out of 10. Typical frost-free season: 257 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Mar 14First frost ~Nov 27Frost season near Cascade Locks, ORSpring: a frost after February 19 in 9 years out of 10, after March 14 in half of the years, after April 4 in 1 year out of 10. Fall: the first frost comes before November 8 in 1 year out of 10, before November 27 in half of the years, before December 15 in 9 years out of 10. Typical frost-free season: 257 days.JFMAMJJASONDLast frost ~Mar 14First frost ~Nov 27
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 4November 8
50% (typical)March 14November 27
90% (likely)February 19December 15
Frost-free season (32°F, 50% chance)
257 days
Hard frost (28°F), last in spring, 50% chance after
February 14
Hard frost (28°F), first in fall, 50% chance before
December 14

The last 15 years (2006–2020 normals)

Typical last frost March 17 (3 days later than the 30-year normal), typical first fall frost November 25 (2 days earlier). Frost-free season 253 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 near Cascade Locks: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 4, 20% March 28, 30% March 24, 40% March 19, 50% March 14, 60% March 10, 70% March 5, 80% February 28, 90% February 19. Observed last spring frost in recent years: 2021 April 13, 2022 April 12, 2023 March 27, 2024 March 8, 2025 March 8, 2026 March 1.Spring: last frostChance of a frost after this date10%50%90%Mar 1Apr 1Apr 4Mar 14Feb 192021: April 132022: April 122023: March 272024: March 82025: March 82026: March 1Fall near Cascade Locks: chance of a frost before this dateFall, chance of a frost before the date: 10% November 8, 20% November 13, 30% November 18, 40% November 23, 50% November 27, 60% December 1, 70% December 4, 80% December 8, 90% December 15. Observed first fall frost in recent years: 2021 December 16, 2022 November 9, 2023 November 24, 2024 October 26, 2025 December 31.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Jan 1Nov 8Nov 27Dec 152021: December 162022: November 92023: November 242024: October 262025: December 31
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 13December 16
2022April 12November 9
2023March 27November 24
2024March 8October 26
2025March 8December 31
2026March 1season not over yet

What these dates mean

The 257 days between the 32°F 50% dates in the Cascade Locks area outline the span in which most tender crops can be grown.

For a gardener, the 50% spring date is March 14, which marks an even chance of a light frost occurring later, and the 50% fall date is November 27, an even chance of a light frost occurring earlier. The cautious spring date for setting out tender crops is April 4, the point at which only a 10% chance of a later frost remains. The cautious fall date to finish harvesting tender crops is November 8, when there is only a 10% chance that a frost has already arrived.

A hard frost at 28°F, represented by the February 14 and December 14 50% dates, can damage plants that would survive a 32°F light frost, so it matters more.

How to read the probabilities

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

  • Spring: "10% after April 4" 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 8" 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 Cascade Locks, ORNumbered nearest stations: 1 — near Carson, WA — 16 mi; 2 — near Sandy, OR — 16 mi; 3 — Government Camp, OR — 25 mi; 4 — Battle Ground, WA — 29 mi; 5 — Estacada, OR — 31 mi.WA25 mi · 40 km1. near Carson, WA — 16 mi12. near Sandy, OR — 16 mi23. Government Camp, OR — 25 mi34. Battle Ground, WA — 29 mi45. Estacada, OR — 31 mi5
  1. near Carson, WA 16 mi (26 km)
  2. near Sandy, OR 16 mi (26 km)
  3. Government Camp, OR 25 mi (41 km)
  4. Battle Ground, WA 29 mi (47 km)
  5. Estacada, OR 31 mi (50 km)

Sources

* Hardiness zone 8b: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 45.6353, -121.9522.