U.S. Frost Dates by Weather Station

NOAA station USC00452007 · Washington

Frost Dates for Davenport, WA

NOAA weather station Davenport (USC00452007), Washington · elevation 2369 ft (722 m) · hardiness zone 6b*

  • Lower-risk planting dateafter July 5only 1 spring in 10 still has a frost later
  • Typical last frostJune 650% chance of a frost after it
  • Typical first fall frostSeptember 1150% chance of a frost before it
  • Frost-free season94 daystypical year, 32°F
  • Hardiness zone6bcalculated*

The year at a glance

Frost season at Davenport, WASpring: a frost after May 13 in 9 years out of 10, after June 6 in half of the years, after July 5 in 1 year out of 10. Fall: the first frost comes before August 26 in 1 year out of 10, before September 11 in half of the years, before September 28 in 9 years out of 10. Typical frost-free season: 94 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Jun 6First frost ~Sep 11Frost season at Davenport, WASpring: a frost after May 13 in 9 years out of 10, after June 6 in half of the years, after July 5 in 1 year out of 10. Fall: the first frost comes before August 26 in 1 year out of 10, before September 11 in half of the years, before September 28 in 9 years out of 10. Typical frost-free season: 94 days.JFMAMJJASONDLast frost ~Jun 6First frost ~Sep 11
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)July 5August 26
50% (typical)June 6September 11
90% (likely)May 13September 28
Frost-free season (32°F, 50% chance)
94 days
Hard frost (28°F), last in spring, 50% chance after
May 11
Hard frost (28°F), first in fall, 50% chance before
September 27

The last 15 years (2006–2020 normals)

Typical last frost June 7 (1 day later than the 30-year normal), typical first fall frost September 9 (2 days earlier). Frost-free season 96 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 Davenport: chance of a frost after this dateSpring, chance of a frost after the date: 10% July 5, 20% June 24, 30% June 17, 40% June 12, 50% June 6, 60% June 1, 70% May 27, 80% May 20, 90% May 13. Observed last spring frost in recent years: 2021 June 11, 2022 May 22, 2023 June 19, 2024 June 28, 2025 May 21, 2026 June 12.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1Jul 1Jul 5Jun 6May 132021: June 112022: May 222023: June 192024: June 282025: May 212026: June 12Fall at Davenport: chance of a frost before this dateFall, chance of a frost before the date: 10% August 26, 20% September 1, 30% September 4, 40% September 7, 50% September 11, 60% September 14, 70% September 18, 80% September 22, 90% September 28. Observed first fall frost in recent years: 2021 August 23, 2022 September 17, 2023 September 19, 2024 September 21, 2025 September 26.Fall: first frostChance of a frost before this date10%50%90%Sep 1Oct 1Aug 26Sep 11Sep 282021: August 232022: September 172023: September 192024: September 212025: September 26
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
2021June 11August 23
2022May 22September 17
2023June 19September 19
2024June 28September 21
2025May 21September 26
2026June 12season not over yet

What these dates mean

July 5 is the cautious spring date, with only a 10 % chance of a light frost later, and it permits a gardener to set out tender crops with minimal risk. The 50 % date in spring is June 6, meaning the odds of a frost occurring later or earlier are even; it does not itself mark a frost event. The hard-frost 50 % date in spring is May 11, indicating the median point for temperatures reaching 28 °F, which can be more damaging than a light frost.

In the fall, August 26 is the cautious date, offering just a 10 % chance that a light frost has arrived earlier, and it is the point at which a gardener can finish harvesting tender crops. The 50 % fall date for light frost is September 11, and the hard-frost 50 % date is September 27. A hard frost matters more because 28 °F can injure or kill plants that would survive the milder 32 °F light frost.

How to read the probabilities

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

  • Spring: "10% after July 5" 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 August 26" 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 Davenport, WANumbered nearest stations: 1 — Wilbur, WA — 27 mi; 2 — Spokane, WA — 30 mi; 3 — Odessa, WA — 34 mi; 4 — Ritzville, WA — 39 mi; 5 — Coulee Dam, WA — 44 mi.WAID25 mi · 40 km1. Wilbur, WA — 27 mi12. Spokane, WA — 30 mi23. Odessa, WA — 34 mi34. Ritzville, WA — 39 mi45. Coulee Dam, WA — 44 mi5
  1. Wilbur, WA 27 mi (44 km)
  2. Spokane, WA 30 mi (48 km)
  3. Odessa, WA 34 mi (54 km)
  4. Ritzville, WA 39 mi (62 km)
  5. Coulee Dam, WA 44 mi (71 km)

Sources

* Hardiness zone 6b: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 47.6575, -118.1614.