U.S. Frost Dates by Weather Station

NOAA station USC00148578 · Kansas

Frost Dates for Washington, KS

NOAA weather station Washington (USC00148578), Kansas · elevation 1305 ft (398 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 8only 1 spring in 10 still has a frost later
  • Typical last frostApril 2450% chance of a frost after it
  • Typical first fall frostOctober 1450% chance of a frost before it
  • Frost-free season171 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Washington, KSSpring: a frost after April 10 in 9 years out of 10, after April 24 in half of the years, after May 8 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 October 25 in 9 years out of 10. Typical frost-free season: 171 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 24First frost ~Oct 14Frost season at Washington, KSSpring: a frost after April 10 in 9 years out of 10, after April 24 in half of the years, after May 8 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 October 25 in 9 years out of 10. Typical frost-free season: 171 days.JFMAMJJASONDLast frost ~Apr 24First 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 30 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 8September 29
50% (typical)April 24October 14
90% (likely)April 10October 25
Frost-free season (32°F, 50% chance)
171 days
Hard frost (28°F), last in spring, 50% chance after
April 14
Hard frost (28°F), first in fall, 50% chance before
October 23

The last 15 years (2006–2020 normals)

Typical last frost April 23 (1 day earlier than the 30-year normal), typical first fall frost October 17 (3 days later). Frost-free season 176 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 Washington: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 8, 20% May 4, 30% April 30, 40% April 27, 50% April 24, 60% April 21, 70% April 18, 80% April 15, 90% April 10. Observed last spring frost in recent years: 2021 April 22, 2022 April 26, 2023 May 3, 2024 April 21, 2025 April 12, 2026 May 1.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 8Apr 24Apr 102021: April 222022: April 262023: May 32024: April 212025: April 122026: May 1Fall at Washington: chance of a frost before this dateFall, chance of a frost before the date: 10% September 29, 20% October 3, 30% October 8, 40% October 11, 50% October 14, 60% October 17, 70% October 19, 80% October 22, 90% October 25. Observed first fall frost in recent years: 2021 October 22, 2022 October 8, 2023 October 28, 2024 October 14, 2025 October 22.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 29Oct 14Oct 252021: October 222022: October 82023: October 282024: October 142025: October 22
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 22October 22
2022April 26October 8
2023May 3October 28
2024April 21October 14
2025April 12October 22
2026May 1season not over yet

What these dates mean

May 8 is the cautious spring date for Washington, Kansas; with only a 10 % chance of a light frost later, it lets a gardener schedule the final setting-out of tender crops. By contrast, planting on April 10 carries a 90 % chance of a later frost and is a gamble, while April 24 is the 50 % date, the median point where a light frost is equally likely or unlikely. The 50 % dates simply mark the even-odds moment for a 32 °F frost.

September 29 is the cautious fall date, offering a 10 % chance that a light frost has already arrived and therefore a reliable time to finish harvesting tender crops. October 25 is a gamble with a 90 % chance of an earlier frost, and October 14 serves as the 50 % median for fall. A hard frost at 28 °F, marked by the dates April 14 and October 23, can injure plants more severely than a 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 May 8" 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 Washington, KSNumbered nearest stations: 1 — Fairbury, NE — 19 mi; 2 — Marysville, KS — 22 mi; 3 — Clay Center, KS — 30 mi; 4 — Belleville, KS — 31 mi; 5 — Concordia, KS — 36 mi.NE25 mi · 40 km1. Fairbury, NE — 19 mi12. Marysville, KS — 22 mi23. Clay Center, KS — 30 mi34. Belleville, KS — 31 mi45. Concordia, KS — 36 mi5
  1. Fairbury, NE 19 mi (31 km)
  2. Marysville, KS 22 mi (36 km)
  3. Clay Center, KS 30 mi (49 km)
  4. Belleville, KS 31 mi (50 km)
  5. Concordia, KS 36 mi (58 km)

Sources

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

Station coordinates: 39.8089, -97.055.