U.S. Frost Dates by Weather Station

NOAA station USC00145888 · Kansas

Frost Dates for Oakley, KS

NOAA weather station Oakley 4 W (USC00145888), Kansas · elevation 3102 ft (946 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 18only 1 spring in 10 still has a frost later
  • Typical last frostMay 650% chance of a frost after it
  • Typical first fall frostOctober 950% chance of a frost before it
  • Frost-free season156 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Oakley, KSSpring: a frost after April 22 in 9 years out of 10, after May 6 in half of the years, after May 18 in 1 year out of 10. Fall: the first frost comes before September 27 in 1 year out of 10, before October 9 in half of the years, before October 21 in 9 years out of 10. Typical frost-free season: 156 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 6First frost ~Oct 9Frost season at Oakley, KSSpring: a frost after April 22 in 9 years out of 10, after May 6 in half of the years, after May 18 in 1 year out of 10. Fall: the first frost comes before September 27 in 1 year out of 10, before October 9 in half of the years, before October 21 in 9 years out of 10. Typical frost-free season: 156 days.JFMAMJJASONDLast frost ~May 6First frost ~Oct 9
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 18September 27
50% (typical)May 6October 9
90% (likely)April 22October 21
Frost-free season (32°F, 50% chance)
156 days
Hard frost (28°F), last in spring, 50% chance after
April 27
Hard frost (28°F), first in fall, 50% chance before
October 18

The last 15 years (2006–2020 normals)

Typical last frost May 6 (same as the 30-year normal), typical first fall frost October 10 (1 day later). Frost-free season 158 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 Oakley: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 18, 20% May 13, 30% May 10, 40% May 8, 50% May 6, 60% May 3, 70% May 1, 80% April 28, 90% April 22. Observed last spring frost in recent years: 2021 May 12, 2022 May 2, 2023 May 1, 2024 April 21, 2026 May 3.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 18May 6Apr 222021: May 122022: May 22023: May 12024: April 212026: May 3Fall at Oakley: chance of a frost before this dateFall, chance of a frost before the date: 10% September 27, 20% October 1, 30% October 4, 40% October 6, 50% October 9, 60% October 11, 70% October 14, 80% October 17, 90% October 21. Observed first fall frost in recent years: 2021 October 15, 2022 October 15, 2023 October 7, 2025 October 19.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 27Oct 9Oct 212021: October 152022: October 152023: October 72025: October 19
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
2021May 12October 15
2022May 2October 15
2023May 1October 7
2024April 21incomplete record
2025incomplete recordOctober 19
2026May 3season not over yet

What these dates mean

Planting tender crops on April 22 in Oakley is a gamble, because a 90 % chance of a light frost later than that date still exists. Gardeners who prefer a lower risk wait until the cautious spring date of May 18, when only a 10 % chance of a later frost remains.

The spring 50% light-frost date is May 6 and the fall 50% light-frost date is October 9; each marks the point where an even chance of a frost later (spring) or earlier (fall) occurs. For a cautious fall schedule the 10 % date is September 27, while counting on crops through October 21 carries a 90 % chance of an earlier frost. The spring hard-frost 50% date is April 27 and the fall hard-frost 50% date is October 18, and a hard frost at 28 °F can damage plant tissue more severely than a light frost at 32 °F.

These dates are drawn from 30 years of NOAA normals for the Oakley station.

How to read the probabilities

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

  • Spring: "10% after May 18" 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 27" 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 Oakley, KSNumbered nearest stations: 1 — Colby, KS — 20 mi; 2 — Brewster, KS — 32 mi; 3 — Quinter, KS — 38 mi; 4 — Healy, KS — 40 mi; 5 — Goodland, KS — 44 mi.KSCO25 mi · 40 km1. Colby, KS — 20 mi12. Brewster, KS — 32 mi23. Quinter, KS — 38 mi34. Healy, KS — 40 mi45. Goodland, KS — 44 mi5
  1. Colby, KS 20 mi (33 km)
  2. Brewster, KS 32 mi (52 km)
  3. Quinter, KS 38 mi (61 km)
  4. Healy, KS 40 mi (64 km)
  5. Goodland, KS 44 mi (71 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: 39.1131, -100.9447.