U.S. Frost Dates by Weather Station

NOAA station USC00453883 · Washington

Frost Dates near Burbank, WA

NOAA weather station Ice Harbor Dam (USC00453883), Washington · elevation 368 ft (112 m) · hardiness zone 7b*

Burbank is the nearest town to the station (7.1 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 30only 1 spring in 10 still has a frost later
  • Typical last frostApril 750% chance of a frost after it
  • Typical first fall frostOctober 2250% chance of a frost before it
  • Frost-free season199 daystypical year, 32°F
  • Hardiness zone7bcalculated*

The year at a glance

Frost season near Burbank, WASpring: a frost after March 20 in 9 years out of 10, after April 7 in half of the years, after April 30 in 1 year out of 10. Fall: the first frost comes before October 6 in 1 year out of 10, before October 22 in half of the years, before November 9 in 9 years out of 10. Typical frost-free season: 199 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 7First frost ~Oct 22Frost season near Burbank, WASpring: a frost after March 20 in 9 years out of 10, after April 7 in half of the years, after April 30 in 1 year out of 10. Fall: the first frost comes before October 6 in 1 year out of 10, before October 22 in half of the years, before November 9 in 9 years out of 10. Typical frost-free season: 199 days.JFMAMJJASONDLast frost ~Apr 7First frost ~Oct 22
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 27 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)April 30October 6
50% (typical)April 7October 22
90% (likely)March 20November 9
Frost-free season (32°F, 50% chance)
199 days
Hard frost (28°F), last in spring, 50% chance after
March 18
Hard frost (28°F), first in fall, 50% chance before
November 4

The last 15 years (2006–2020 normals)

Typical last frost April 8 (1 day later than the 30-year normal), typical first fall frost October 22. Frost-free season 199 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 Burbank: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 30, 20% April 23, 30% April 17, 40% April 11, 50% April 7, 60% April 3, 70% March 31, 80% March 27, 90% March 20. Observed last spring frost in recent years: 2021 April 20, 2022 April 7.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1Apr 30Apr 7Mar 202021: April 202022: April 7Fall near Burbank: chance of a frost before this dateFall, chance of a frost before the date: 10% October 6, 20% October 10, 30% October 15, 40% October 19, 50% October 22, 60% October 26, 70% October 29, 80% November 2, 90% November 9. Observed first fall frost in recent years: 2021 October 12, 2022 November 9.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 6Oct 22Nov 92021: October 122022: November 9
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 20October 12
2022April 7November 9
2023incomplete recordincomplete record
2024incomplete recordincomplete record
2025no datano data
2026incomplete recordseason not over yet

What these dates mean

October 6 is the cautious fall date in the Burbank area for finishing the harvest. It marks a 10 % chance that a light frost has arrived earlier, so tender crops should be pulled before then. The 50 % fall date, October 22, represents even odds for a light frost, while November 9 carries a 90 % chance that a light frost will have occurred, making a late harvest a gamble. The hard-frost median dates are March 18 in spring and November 4 in fall.

The cautious spring date for setting out tender crops is April 30, when only a 10 % chance of a later light frost remains. By contrast, March 20 bears a 90 % chance of a later light frost, so planting then is risky, and the 50 % spring date is April 7. A hard frost at 28 °F can damage plants more severely than a light frost at 32 °F because the colder temperature causes deeper tissue injury.

How to read the probabilities

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

  • Spring: "10% after April 30" 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 6" 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 Burbank, WANumbered nearest stations: 1 — Kennewick, WA — 11 mi; 2 — Richland, WA — 19 mi; 3 — Whitman Mission, WA — 24 mi; 4 — Walla Walla, WA — 30 mi; 5 — Milton Freewater, OR — 31 mi.OR25 mi · 40 km1. Kennewick, WA — 11 mi12. Richland, WA — 19 mi23. Whitman Mission, WA — 24 mi34. Walla Walla, WA — 30 mi45. Milton Freewater, OR — 31 mi5
  1. Kennewick, WA 11 mi (18 km)
  2. Richland, WA 19 mi (30 km)
  3. Whitman Mission, WA 24 mi (39 km)
  4. Walla Walla, WA 30 mi (49 km)
  5. Milton Freewater, OR 31 mi (49 km)

Sources

* Hardiness zone 7b: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 46.2447, -118.8786.