U.S. Frost Dates by Weather Station

NOAA station USC00250760 · Nebraska

Frost Dates for Benkelman, NE

NOAA weather station Benkelman 1 N (USC00250760), Nebraska · elevation 3081 ft (939 m) · hardiness zone 5b*

  • Lower-risk planting dateafter May 12only 1 spring in 10 still has a frost later
  • Typical last frostApril 3050% chance of a frost after it
  • Typical first fall frostOctober 1250% chance of a frost before it
  • Frost-free season163 daystypical year, 32°F
  • Hardiness zone5bcalculated*

The year at a glance

Frost season at Benkelman, NESpring: a frost after April 17 in 9 years out of 10, after April 30 in half of the years, after May 12 in 1 year out of 10. Fall: the first frost comes before September 29 in 1 year out of 10, before October 12 in half of the years, before October 22 in 9 years out of 10. Typical frost-free season: 163 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 30First frost ~Oct 12Frost season at Benkelman, NESpring: a frost after April 17 in 9 years out of 10, after April 30 in half of the years, after May 12 in 1 year out of 10. Fall: the first frost comes before September 29 in 1 year out of 10, before October 12 in half of the years, before October 22 in 9 years out of 10. Typical frost-free season: 163 days.JFMAMJJASONDLast frost ~Apr 30First frost ~Oct 12
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 28 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 12September 29
50% (typical)April 30October 12
90% (likely)April 17October 22
Frost-free season (32°F, 50% chance)
163 days
Hard frost (28°F), last in spring, 50% chance after
April 19
Hard frost (28°F), first in fall, 50% chance before
October 20

The last 15 years (2006–2020 normals)

Typical last frost April 30 (same as the 30-year normal), typical first fall frost October 13 (1 day later). Frost-free season 164 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 Benkelman: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 12, 20% May 7, 30% May 4, 40% May 2, 50% April 30, 60% April 28, 70% April 25, 80% April 21, 90% April 17. Observed last spring frost in recent years: 2021 April 23, 2022 May 4.Spring: last frostChance of a frost after this date10%50%90%May 1May 12Apr 30Apr 172021: April 232022: May 4Fall at Benkelman: chance of a frost before this dateFall, chance of a frost before the date: 10% September 29, 20% October 4, 30% October 7, 40% October 9, 50% October 12, 60% October 14, 70% October 16, 80% October 19, 90% October 22. Observed first fall frost in recent years: 2021 October 13, 2022 October 16.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 29Oct 12Oct 222021: October 132022: October 16
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 23October 13
2022May 4October 16
2023no datano data
2024no datano data
2025no datano data
2026no dataseason not over yet

What these dates mean

May 12 is the cautious spring date, with only a ten percent chance of a light frost occurring later; this lets a gardener plan to set out tender crops with relatively low risk. The fifty-percent spring date, April 30, marks the point where a frost is equally likely or unlikely, and the fifty-percent fall date, October 12, does the same for autumn. The hard-frost median dates are April 19 in spring and October 20 in fall, and they indicate when temperatures dropping to twenty-eight degrees Fahrenheit become a fifty-percent possibility.

September 29 serves as the cautious fall date, carrying a ten percent chance that a light frost has arrived earlier, so it is the preferred day to finish harvesting tender crops. A hard frost matters more than a light frost because twenty-eight degrees can damage plant tissue that survives thirty-two degrees.

How to read the probabilities

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

  • Spring: "10% after May 12" 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 Benkelman, NENumbered nearest stations: 1 — Saint Francis, KS — 25 mi; 2 — near Trenton, NE — 27 mi; 3 — Atwood, KS — 32 mi; 4 — Wray, CO — 35 mi; 5 — Culbertson, NE — 39 mi.KSNE25 mi · 40 km1. Saint Francis, KS — 25 mi12. near Trenton, NE — 27 mi23. Atwood, KS — 32 mi34. Wray, CO — 35 mi45. Culbertson, NE — 39 mi5
  1. Saint Francis, KS 25 mi (40 km)
  2. near Trenton, NE 27 mi (43 km)
  3. Atwood, KS 32 mi (52 km)
  4. Wray, CO 35 mi (56 km)
  5. Culbertson, 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: 40.0644, -101.5436.