U.S. Frost Dates by Weather Station

NOAA station USC00252065 · Nebraska

Frost Dates for Culbertson, NE

NOAA weather station Culbertson (USC00252065), Nebraska · elevation 2581 ft (787 m) · hardiness zone 5b*

  • Lower-risk planting dateafter May 13only 1 spring in 10 still has a frost later
  • Typical last frostMay 250% chance of a frost after it
  • Typical first fall frostOctober 950% chance of a frost before it
  • Frost-free season158 daystypical year, 32°F
  • Hardiness zone5bcalculated*

The year at a glance

Frost season at Culbertson, NESpring: a frost after April 19 in 9 years out of 10, after May 2 in half of the years, after May 13 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 20 in 9 years out of 10. Typical frost-free season: 158 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 2First frost ~Oct 9Frost season at Culbertson, NESpring: a frost after April 19 in 9 years out of 10, after May 2 in half of the years, after May 13 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 20 in 9 years out of 10. Typical frost-free season: 158 days.JFMAMJJASONDLast frost ~May 2First 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 29 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 13September 27
50% (typical)May 2October 9
90% (likely)April 19October 20
Frost-free season (32°F, 50% chance)
158 days
Hard frost (28°F), last in spring, 50% chance after
April 23
Hard frost (28°F), first in fall, 50% chance before
October 18

The last 15 years (2006–2020 normals)

Typical last frost May 1 (1 day earlier than the 30-year normal), typical first fall frost October 10 (1 day later). Frost-free season 160 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 Culbertson: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 13, 20% May 9, 30% May 6, 40% May 4, 50% May 2, 60% May 1, 70% April 28, 80% April 24, 90% April 19. Observed last spring frost in recent years: 2021 May 13, 2022 May 4, 2023 May 3, 2024 April 22, 2025 April 20, 2026 May 3.Spring: last frostChance of a frost after this date10%50%90%May 1May 13May 2Apr 192021: May 132022: May 42023: May 32024: April 222025: April 202026: May 3Fall at Culbertson: chance of a frost before this dateFall, chance of a frost before the date: 10% September 27, 20% October 1, 30% October 3, 40% October 6, 50% October 9, 60% October 11, 70% October 13, 80% October 16, 90% October 20. Observed first fall frost in recent years: 2021 September 23, 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 27Oct 9Oct 202021: September 232022: 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
2021May 13September 23
2022May 4October 17
2023May 3October 7
2024April 22October 14
2025April 20October 19
2026May 3season not over yet

What these dates mean

There are 158 days between the 32°F 50% dates in Culbertson, and within that window gardeners can plant, grow, and harvest tender crops.

The 32°F 50% date in spring is May 2, and the 32°F 50% date in fall is October 9; neither marks a frost event but shows the point at which the chance of a frost is even. The cautious spring date for setting out tender crops is May 13, which carries only a 10% chance of a later frost, while the cautious fall date to finish harvesting tender crops is September 27, with only a 10% chance that a frost has arrived earlier. By contrast, planting on April 19 or counting on crops through October 20 involves a 90% chance of frost and is a gamble.

Hard frost at 28°F can damage plants that survive a light frost at 32°F.

How to read the probabilities

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

  • Spring: "10% after May 13" 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 Culbertson, NENumbered nearest stations: 1 — near Trenton, NE — 13 mi; 2 — Hayes Center, NE — 23 mi; 3 — Atwood, KS — 32 mi; 4 — Cambridge, NE — 36 mi; 5 — Benkelman, NE — 39 mi.NEKS25 mi · 40 km1. near Trenton, NE — 13 mi12. Hayes Center, NE — 23 mi23. Atwood, KS — 32 mi34. Cambridge, NE — 36 mi45. Benkelman, NE — 39 mi5
  1. near Trenton, NE 13 mi (21 km)
  2. Hayes Center, NE 23 mi (37 km)
  3. Atwood, KS 32 mi (51 km)
  4. Cambridge, NE 36 mi (59 km)
  5. Benkelman, NE 39 mi (63 km)

Sources

* Hardiness zone 5b: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 40.2317, -100.8303.