U.S. Frost Dates by Weather Station

NOAA station USC00258920 · Nebraska

Frost Dates for Wallace, NE

NOAA weather station Wallace 2 W (USC00258920), Nebraska · elevation 3153 ft (961 m) · hardiness zone 5b*

  • Lower-risk planting dateafter May 16only 1 spring in 10 still has a frost later
  • Typical last frostMay 450% chance of a frost after it
  • Typical first fall frostOctober 450% chance of a frost before it
  • Frost-free season152 daystypical year, 32°F
  • Hardiness zone5bcalculated*

The year at a glance

Frost season at Wallace, NESpring: a frost after April 23 in 9 years out of 10, after May 4 in half of the years, after May 16 in 1 year out of 10. Fall: the first frost comes before September 23 in 1 year out of 10, before October 4 in half of the years, before October 16 in 9 years out of 10. Typical frost-free season: 152 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 4First frost ~Oct 4Frost season at Wallace, NESpring: a frost after April 23 in 9 years out of 10, after May 4 in half of the years, after May 16 in 1 year out of 10. Fall: the first frost comes before September 23 in 1 year out of 10, before October 4 in half of the years, before October 16 in 9 years out of 10. Typical frost-free season: 152 days.JFMAMJJASONDLast frost ~May 4First frost ~Oct 4
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 16September 23
50% (typical)May 4October 4
90% (likely)April 23October 16
Frost-free season (32°F, 50% chance)
152 days
Hard frost (28°F), last in spring, 50% chance after
April 25
Hard frost (28°F), first in fall, 50% chance before
October 14

The last 15 years (2006–2020 normals)

Typical last frost May 7 (3 days later than the 30-year normal), typical first fall frost October 7 (3 days later). Frost-free season 152 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 Wallace: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 16, 20% May 12, 30% May 9, 40% May 7, 50% May 4, 60% May 2, 70% April 30, 80% April 27, 90% April 23. Observed last spring frost in recent years: 2021 May 13, 2022 May 22, 2023 May 3, 2024 May 4, 2025 May 4.Spring: last frostChance of a frost after this date10%50%90%May 1May 16May 4Apr 232021: May 132022: May 222023: May 32024: May 42025: May 4Fall at Wallace: chance of a frost before this dateFall, chance of a frost before the date: 10% September 23, 20% September 27, 30% September 30, 40% October 2, 50% October 4, 60% October 6, 70% October 10, 80% October 12, 90% October 16. Observed first fall frost in recent years: 2021 October 14, 2022 October 8, 2023 October 7, 2024 September 24, 2025 October 19.Fall: first frostChance of a frost before this date10%50%90%Oct 1Sep 23Oct 4Oct 162021: October 142022: October 82023: October 72024: September 242025: 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 13October 14
2022May 22October 8
2023May 3October 7
2024May 4September 24
2025May 4October 19
2026incomplete recordseason not over yet

What these dates mean

September 23 is the cautious fall date to finish harvesting tender crops, because there is only a 10 % chance that a light frost has arrived earlier. In spring the cautious date for setting out tender crops is May 16, when a light frost later than that date occurs with only a 10 % chance; planting on April 23 carries a 90 % chance of frost and is a gamble.

For a gardener the 50 % light-frost dates are May 4 and October 4; each marks the point at which an even odds of a frost exists, but they are not frost dates themselves. The 50 % hard-frost dates are April 25 in spring and October 14 in fall, providing a reference for when temperatures of 28 °F become equally likely.

A hard frost at 28 °F can injure plants that would otherwise survive a light frost at 32 °F, making the hard-frost threshold a more critical concern.

How to read the probabilities

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

  • Spring: "10% after May 16" 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 23" 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 Wallace, NENumbered nearest stations: 1 — Madrid, NE — 17 mi; 2 — Hershey, NE — 22 mi; 3 — Hayes Center, NE — 24 mi; 4 — near North Platte, NE — 28 mi; 5 — Ogallala, NE — 33 mi.CO25 mi · 40 km1. Madrid, NE — 17 mi12. Hershey, NE — 22 mi23. Hayes Center, NE — 24 mi34. near North Platte, NE — 28 mi45. Ogallala, NE — 33 mi5
  1. Madrid, NE 17 mi (28 km)
  2. Hershey, NE 22 mi (35 km)
  3. Hayes Center, NE 24 mi (39 km)
  4. near North Platte, NE 28 mi (45 km)
  5. Ogallala, NE 33 mi (53 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: 40.8433, -101.2094.