U.S. Frost Dates by Weather Station

NOAA station USC00140439 · Kansas

Frost Dates for Atwood, KS

NOAA weather station Atwood (USC00140439), Kansas · elevation 2893 ft (882 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 14only 1 spring in 10 still has a frost later
  • Typical last frostMay 250% chance of a frost after it
  • Typical first fall frostOctober 850% chance of a frost before it
  • Frost-free season157 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Atwood, KSSpring: a frost after April 20 in 9 years out of 10, after May 2 in half of the years, after May 14 in 1 year out of 10. Fall: the first frost comes before September 25 in 1 year out of 10, before October 8 in half of the years, before October 20 in 9 years out of 10. Typical frost-free season: 157 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 2First frost ~Oct 8Frost season at Atwood, KSSpring: a frost after April 20 in 9 years out of 10, after May 2 in half of the years, after May 14 in 1 year out of 10. Fall: the first frost comes before September 25 in 1 year out of 10, before October 8 in half of the years, before October 20 in 9 years out of 10. Typical frost-free season: 157 days.JFMAMJJASONDLast frost ~May 2First frost ~Oct 8
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 14September 25
50% (typical)May 2October 8
90% (likely)April 20October 20
Frost-free season (32°F, 50% chance)
157 days
Hard frost (28°F), last in spring, 50% chance after
April 22
Hard frost (28°F), first in fall, 50% chance before
October 17

The last 15 years (2006–2020 normals)

Typical last frost May 2 (same as the 30-year normal), typical first fall frost October 10 (2 days later). Frost-free season 159 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 Atwood: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 14, 20% May 9, 30% May 6, 40% May 4, 50% May 2, 60% April 30, 70% April 28, 80% April 23, 90% April 20. Observed last spring frost in recent years: 2021 April 24, 2022 May 2, 2023 May 3, 2024 April 22, 2025 May 4, 2026 May 3.Spring: last frostChance of a frost after this date10%50%90%May 1May 14May 2Apr 202021: April 242022: May 22023: May 32024: April 222025: May 42026: May 3Fall at Atwood: chance of a frost before this dateFall, chance of a frost before the date: 10% September 25, 20% September 30, 30% October 3, 40% October 6, 50% October 8, 60% October 10, 70% October 13, 80% October 16, 90% October 20. Observed first fall frost in recent years: 2021 October 14, 2022 October 17, 2023 October 7, 2024 October 14, 2025 October 19.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 25Oct 8Oct 202021: October 142022: October 172023: October 72024: October 142025: 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
2021April 24October 14
2022May 2October 17
2023May 3October 7
2024April 22October 14
2025May 4October 19
2026May 3season not over yet

What these dates mean

September 25 marks the cautious fall date for finishing the harvest in Atwood, with only a 10 % chance that a light frost has arrived earlier. In spring the cautious date for setting out tender crops is May 14, when the chance of a light frost later than that day is just 10 %; planting on April 20 carries a 90 % chance of a frost and is a gamble.

The 50 % light-frost dates are May 2 and October 8; each represents an even-odds point for a light frost. Gardeners can view these dates as the midpoint of the frost-free window, which spans 157 days between the two 32 °F 50 % dates. The 50 % hard-frost dates are April 22 in spring and October 17 in fall.

Hard frost at 28 °F is more damaging than a 32 °F light frost because it can injure or kill plants that would otherwise survive the milder temperature.

How to read the probabilities

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

  • Spring: "10% after May 14" 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 25" 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 Atwood, KSNumbered nearest stations: 1 — near Trenton, NE — 27 mi; 2 — Colby, KS — 28 mi; 3 — Culbertson, NE — 32 mi; 4 — Benkelman, NE — 32 mi; 5 — Brewster, KS — 37 mi.KSCO25 mi · 40 km1. near Trenton, NE — 27 mi12. Colby, KS — 28 mi23. Culbertson, NE — 32 mi34. Benkelman, NE — 32 mi45. Brewster, KS — 37 mi5
  1. near Trenton, NE 27 mi (44 km)
  2. Colby, KS 28 mi (45 km)
  3. Culbertson, NE 32 mi (51 km)
  4. Benkelman, NE 32 mi (52 km)
  5. Brewster, KS 37 mi (59 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: 39.7994, -101.0422.