U.S. Frost Dates by Weather Station

NOAA station USC00452531 · Washington

Frost Dates for Elma, WA

NOAA weather station Elma (USC00452531), Washington · elevation 70 ft (21 m) · hardiness zone 8b*

  • Lower-risk planting dateafter May 19only 1 spring in 10 still has a frost later
  • Typical last frostMay 150% chance of a frost after it
  • Typical first fall frostOctober 1450% chance of a frost before it
  • Frost-free season169 daystypical year, 32°F
  • Hardiness zone8bcalculated*

The year at a glance

Frost season at Elma, WASpring: a frost after April 11 in 9 years out of 10, after May 1 in half of the years, after May 19 in 1 year out of 10. Fall: the first frost comes before September 29 in 1 year out of 10, before October 14 in half of the years, before November 4 in 9 years out of 10. Typical frost-free season: 169 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 1First frost ~Oct 14Frost season at Elma, WASpring: a frost after April 11 in 9 years out of 10, after May 1 in half of the years, after May 19 in 1 year out of 10. Fall: the first frost comes before September 29 in 1 year out of 10, before October 14 in half of the years, before November 4 in 9 years out of 10. Typical frost-free season: 169 days.JFMAMJJASONDLast frost ~May 1First frost ~Oct 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 28 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 19September 29
50% (typical)May 1October 14
90% (likely)April 11November 4
Frost-free season (32°F, 50% chance)
169 days
Hard frost (28°F), last in spring, 50% chance after
April 3
Hard frost (28°F), first in fall, 50% chance before
November 2

The last 15 years (2006–2020 normals)

Typical last frost May 1 (same as the 30-year normal), typical first fall frost October 12 (2 days earlier). Frost-free season 166 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 Elma: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 19, 20% May 11, 30% May 8, 40% May 4, 50% May 1, 60% April 28, 70% April 24, 80% April 20, 90% April 11. Observed last spring frost in recent years: 2021 April 15, 2022 May 10, 2023 April 20, 2024 May 1, 2025 May 5, 2026 April 17.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1Jun 1May 19May 1Apr 112021: April 152022: May 102023: April 202024: May 12025: May 52026: April 17Fall at Elma: chance of a frost before this dateFall, chance of a frost before the date: 10% September 29, 20% October 3, 30% October 5, 40% October 9, 50% October 14, 60% October 18, 70% October 23, 80% October 29, 90% November 4. Observed first fall frost in recent years: 2021 October 11, 2022 November 9, 2023 October 26, 2024 November 7, 2025 October 14.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 29Oct 14Nov 42021: October 112022: November 92023: October 262024: November 72025: October 14
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 15October 11
2022May 10November 9
2023April 20October 26
2024May 1November 7
2025May 5October 14
2026April 17season not over yet

What these dates mean

Setting out tender crops on April 11 in Elma is a gamble, because a light frost later that season has a 90% chance of occurring. The 50% spring date of May 1 marks the point at which a light frost is equally likely to arrive before or after, and the 50% fall date of October 14 does the same for autumn. These median dates are not frost dates themselves, but they help gardeners gauge the balance of risk.

For a cautious approach, tender crops are usually placed outdoors after the May 19 light-frost date, which carries only a 10% chance of a later frost, and harvested before the September 29 light-frost date, which also carries a 10% chance of an earlier frost. A hard frost at 28 °F, such as the spring median of April 3 or the fall median of November 2, can harm plants that would survive a 32 °F light frost, making it the more threatening threshold.

How to read the probabilities

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

  • Spring: "10% after May 19" 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 September 29" 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 Elma, WANumbered nearest stations: 1 — Aberdeen, WA — 20 mi; 2 — Olympia, WA — 24 mi; 3 — near Hoquiam, WA — 25 mi; 4 — Cushman Powerhouse #2, WA — 27 mi; 5 — Raymond, WA — 29 mi.25 mi · 40 km1. Aberdeen, WA — 20 mi12. Olympia, WA — 24 mi23. near Hoquiam, WA — 25 mi34. Cushman Powerhouse #2, WA — 27 mi45. Raymond, WA — 29 mi5
  1. Aberdeen, WA 20 mi (33 km)
  2. Olympia, WA 24 mi (38 km)
  3. near Hoquiam, WA 25 mi (40 km)
  4. Cushman Powerhouse #2, WA 27 mi (44 km)
  5. Raymond, WA 29 mi (47 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: 47.0092, -123.4008.