U.S. Frost Dates by Weather Station

NOAA station USC00458278 · Washington

Frost Dates near Tacoma, WA

NOAA weather station Tacoma #1 (USC00458278), Washington · elevation 25 ft (8 m) · hardiness zone 9a*

Tacoma is the nearest town to the station (1.6 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 March 31only 1 spring in 10 still has a frost later
  • Typical last frostMarch 850% chance of a frost after it
  • Typical first fall frostNovember 1450% chance of a frost before it
  • Frost-free season250 daystypical year, 32°F
  • Hardiness zone9acalculated*

The year at a glance

Frost season near Tacoma, WASpring: a frost after February 15 in 9 years out of 10, after March 8 in half of the years, after March 31 in 1 year out of 10. Fall: the first frost comes before October 30 in 1 year out of 10, before November 14 in half of the years, before December 2 in 9 years out of 10. Typical frost-free season: 250 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Mar 8First frost ~Nov 14Frost season near Tacoma, WASpring: a frost after February 15 in 9 years out of 10, after March 8 in half of the years, after March 31 in 1 year out of 10. Fall: the first frost comes before October 30 in 1 year out of 10, before November 14 in half of the years, before December 2 in 9 years out of 10. Typical frost-free season: 250 days.JFMAMJJASONDLast frost ~Mar 8First frost ~Nov 14
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)March 31October 30
50% (typical)March 8November 14
90% (likely)February 15December 2
Frost-free season (32°F, 50% chance)
250 days
Hard frost (28°F), last in spring, 50% chance after
February 11
Hard frost (28°F), first in fall, 50% chance before
December 1

The last 15 years (2006–2020 normals)

Typical last frost March 8 (same as the 30-year normal), typical first fall frost November 17 (3 days later). Frost-free season 254 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 Tacoma: chance of a frost after this dateSpring, chance of a frost after the date: 10% March 31, 20% March 23, 30% March 17, 40% March 12, 50% March 8, 60% March 3, 70% February 28, 80% February 23, 90% February 15. Observed last spring frost in recent years: 2021 March 16, 2022 April 14, 2023 March 27, 2024 March 7, 2025 March 13, 2026 February 25.Spring: last frostChance of a frost after this date10%50%90%Feb 1Mar 1Apr 1Mar 31Mar 8Feb 152021: March 162022: April 142023: March 272024: March 72025: March 132026: February 25Fall near Tacoma: chance of a frost before this dateFall, chance of a frost before the date: 10% October 30, 20% November 3, 30% November 7, 40% November 11, 50% November 14, 60% November 17, 70% November 21, 80% November 26, 90% December 2. Observed first fall frost in recent years: 2021 November 17, 2022 November 9, 2023 October 28, 2024 December 1, 2025 October 18.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Oct 30Nov 14Dec 22021: November 172022: November 92023: October 282024: December 12025: October 18
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
2021March 16November 17
2022April 14November 9
2023March 27October 28
2024March 7December 1
2025March 13October 18
2026February 25season not over yet

What these dates mean

There are 250 days between the 32°F 50% dates in the Tacoma area, giving a long interval for planting, growing and harvesting crops. Within that span the climate record spans 26 years.

The 50% date in spring is March 8, which means a 50% chance of a light frost later than this date, while the 10% cautious date for setting out tender crops is March 31. In fall the 50% date is November 14, indicating a 50% chance of a light frost earlier than this date, and the cautious date to finish harvesting tender crops is October 30. Hard-frost 28°F conditions have their 50% dates on February 11 in spring and December 1 in fall; a hard frost can injure plants that survive a light frost, so it is a greater risk.

How to read the probabilities

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

  • Spring: "10% after March 31" 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 30" 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 Tacoma, WANumbered nearest stations: 1 — Kent, WA — 14 mi; 2 — Seattle (Seattle-Tacoma Airport), WA — 14 mi; 3 — Palmer, WA — 27 mi; 4 — Olympia, WA — 30 mi; 5 — near Kirkland, WA — 31 mi.25 mi · 40 km1. Kent, WA — 14 mi12. Seattle (Seattle-Tacoma Airport), WA — 14 mi23. Palmer, WA — 27 mi34. Olympia, WA — 30 mi45. near Kirkland, WA — 31 mi5
  1. Kent, WA 14 mi (23 km)
  2. Seattle (Seattle-Tacoma Airport), WA 14 mi (23 km)
  3. Palmer, WA 27 mi (43 km)
  4. Olympia, WA 30 mi (48 km)
  5. near Kirkland, WA 31 mi (50 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: 47.2472, -122.4122.