U.S. Frost Dates by Weather Station

NOAA station USW00024032 · Nebraska

Frost Dates near Valentine, NE

NOAA weather station Valentine Miller Field (USW00024032), Nebraska · elevation 2590 ft (789 m) · hardiness zone 5a*

Valentine is the nearest town to the station (0.4 mi away) in GeoNames (CC BY 4.0). The dates below are measured at the station, not in the town itself.

  • Lower-risk planting dateafter May 25only 1 spring in 10 still has a frost later
  • Typical last frostMay 1250% chance of a frost after it
  • Typical first fall frostSeptember 2950% chance of a frost before it
  • Frost-free season140 daystypical year, 32°F
  • Hardiness zone5acalculated*

The year at a glance

Frost season near Valentine, NESpring: a frost after April 30 in 9 years out of 10, after May 12 in half of the years, after May 25 in 1 year out of 10. Fall: the first frost comes before September 16 in 1 year out of 10, before September 29 in half of the years, before October 12 in 9 years out of 10. Typical frost-free season: 140 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 12First frost ~Sep 29Frost season near Valentine, NESpring: a frost after April 30 in 9 years out of 10, after May 12 in half of the years, after May 25 in 1 year out of 10. Fall: the first frost comes before September 16 in 1 year out of 10, before September 29 in half of the years, before October 12 in 9 years out of 10. Typical frost-free season: 140 days.JFMAMJJASONDLast frost ~May 12First frost ~Sep 29
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 27 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 25September 16
50% (typical)May 12September 29
90% (likely)April 30October 12
Frost-free season (32°F, 50% chance)
140 days
Hard frost (28°F), last in spring, 50% chance after
May 2
Hard frost (28°F), first in fall, 50% chance before
October 8

The last 15 years (2006–2020 normals)

Typical last frost May 11 (1 day earlier than the 30-year normal), typical first fall frost October 2 (3 days later). Frost-free season 142 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 near Valentine: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 25, 20% May 21, 30% May 17, 40% May 15, 50% May 12, 60% May 10, 70% May 6, 80% May 3, 90% April 30. Observed last spring frost in recent years: 2021 May 11, 2022 May 22, 2023 May 2, 2024 May 4, 2025 May 3, 2026 May 7.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 25May 12Apr 302021: May 112022: May 222023: May 22024: May 42025: May 32026: May 7Fall near Valentine: chance of a frost before this dateFall, chance of a frost before the date: 10% September 16, 20% September 21, 30% September 25, 40% September 27, 50% September 29, 60% October 2, 70% October 4, 80% October 7, 90% October 12. Observed first fall frost in recent years: 2021 October 14, 2022 September 26, 2023 October 6, 2024 October 1, 2025 October 13.Fall: first frostChance of a frost before this date10%50%90%Oct 1Sep 16Sep 29Oct 122021: October 142022: September 262023: October 62024: October 12025: October 13
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 11October 14
2022May 22September 26
2023May 2October 6
2024May 4October 1
2025May 3October 13
2026May 7season not over yet

What these dates mean

Setting out tender crops on April 30 in the Valentine area carries a 90% chance of a frost, making it a gamble. The cautious spring date for planting tender crops is May 25, when only a 10% chance of a frost later than the date remains. The 50% date is May 12; there is a 50% chance of a frost later than this date.

The cautious fall date to finish harvesting tender crops is September 16, with a 10% chance of a frost earlier than that day. October 12 represents a 90% chance of a frost earlier, so counting on crops that long is a gamble. The 50% date is September 29; there is a 50% chance of a frost earlier than this date.

A hard frost, defined at 28 °F, is more damaging than a light frost at 32 °F because it can kill plant tissue that survives 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 25" 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 16" 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 Valentine, NENumbered nearest stations: 1 — Mission, SD — 16 mi; 2 — Springview, NE — 39 mi; 3 — Ainsworth, NE — 42 mi; 4 — Elsmere, NE — 56 mi; 5 — Gregory, SD — 62 mi.SD25 mi · 40 km1. Mission, SD — 16 mi12. Springview, NE — 39 mi23. Ainsworth, NE — 42 mi34. Elsmere, NE — 56 mi45. Gregory, SD — 62 mi5
  1. Mission, SD 16 mi (26 km)
  2. Springview, NE 39 mi (63 km)
  3. Ainsworth, NE 42 mi (67 km)
  4. Elsmere, NE 56 mi (90 km)
  5. Gregory, SD 62 mi (99 km)

Sources

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

Station coordinates: 42.8783, -100.55.