U.S. Frost Dates by Weather Station

NOAA station USC00451233 · Washington

Frost Dates near Wilderness Rim, WA

NOAA weather station Cedar Lake (USC00451233), Washington · elevation 1560 ft (476 m) · hardiness zone 8b*

Wilderness Rim is the nearest town to the station (2.3 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 May 13only 1 spring in 10 still has a frost later
  • Typical last frostApril 2350% chance of a frost after it
  • Typical first fall frostNovember 150% chance of a frost before it
  • Frost-free season193 daystypical year, 32°F
  • Hardiness zone8bcalculated*

The year at a glance

Frost season near Wilderness Rim, WASpring: a frost after April 3 in 9 years out of 10, after April 23 in half of the years, after May 13 in 1 year out of 10. Fall: the first frost comes before October 17 in 1 year out of 10, before November 1 in half of the years, before November 22 in 9 years out of 10. Typical frost-free season: 193 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 23First frost ~Nov 1Frost season near Wilderness Rim, WASpring: a frost after April 3 in 9 years out of 10, after April 23 in half of the years, after May 13 in 1 year out of 10. Fall: the first frost comes before October 17 in 1 year out of 10, before November 1 in half of the years, before November 22 in 9 years out of 10. Typical frost-free season: 193 days.JFMAMJJASONDLast frost ~Apr 23First frost ~Nov 1
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 26 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 13October 17
50% (typical)April 23November 1
90% (likely)April 3November 22
Frost-free season (32°F, 50% chance)
193 days
Hard frost (28°F), last in spring, 50% chance after
March 24
Hard frost (28°F), first in fall, 50% chance before
November 22

The last 15 years (2006–2020 normals)

Typical last frost April 20 (3 days earlier than the 30-year normal), typical first fall frost November 4 (3 days later). Frost-free season 195 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 Wilderness Rim: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 13, 20% May 6, 30% May 2, 40% April 28, 50% April 23, 60% April 18, 70% April 14, 80% April 9, 90% April 3. Observed last spring frost in recent years: 2021 April 14, 2022 April 21, 2023 April 20, 2024 April 30, 2025 April 14, 2026 April 18.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 13Apr 23Apr 32021: April 142022: April 212023: April 202024: April 302025: April 142026: April 18Fall near Wilderness Rim: chance of a frost before this dateFall, chance of a frost before the date: 10% October 17, 20% October 23, 30% October 27, 40% October 30, 50% November 1, 60% November 6, 70% November 10, 80% November 15, 90% November 22. Observed first fall frost in recent years: 2021 October 12, 2022 November 6, 2023 October 27, 2024 November 16.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Oct 17Nov 1Nov 222021: October 122022: November 62023: October 272024: November 16
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 14October 12
2022April 21November 6
2023April 20October 27
2024April 30November 16
2025April 14incomplete record
2026April 18season not over yet

What these dates mean

May 13 is the cautious spring light-frost date for the Wilderness Rim area; with only a 10 % chance of a frost later, a gardener can schedule the first outdoor placement of tender crops with minimal risk. The earlier April 3 date carries a 90 % chance of frost and is a gamble, while the median April 23 date marks the point where a light frost is as likely as not on those days, framing the central window of low-risk planting.

The median light-frost dates—April 23 in spring and November 1 in fall—tell a gardener that the probability of a frost is roughly even on those days, framing the central window of low-risk planting. For hard frost, the 50 % dates are March 24 and November 22, and a hard frost matters more because 28 °F can damage or kill plants that would survive a 32 °F light frost. The cautious fall light-frost date is October 17, when there is only a 10 % chance that a frost has already arrived, allowing the final harvest of tender crops.

How to read the probabilities

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

  • Spring: "10% after May 13" 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 17" 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 Wilderness Rim, WANumbered nearest stations: 1 — Palmer, WA — 9 mi; 2 — Kent, WA — 23 mi; 3 — Seattle (Seattle-Tacoma Airport), WA — 26 mi; 4 — near Kirkland, WA — 30 mi; 5 — Startup, WA — 31 mi.25 mi · 40 km1. Palmer, WA — 9 mi12. Kent, WA — 23 mi23. Seattle (Seattle-Tacoma Airport), WA — 26 mi34. near Kirkland, WA — 30 mi45. Startup, WA — 31 mi5
  1. Palmer, WA 9 mi (14 km)
  2. Kent, WA 23 mi (37 km)
  3. Seattle (Seattle-Tacoma Airport), WA 26 mi (42 km)
  4. near Kirkland, WA 30 mi (48 km)
  5. Startup, WA 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: 47.4144, -121.7561.