U.S. Frost Dates by Weather Station

NOAA station USC00054834 · Colorado

Frost Dates for Las Animas, CO

NOAA weather station Las Animas (USC00054834), Colorado · elevation 3890 ft (1186 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 11only 1 spring in 10 still has a frost later
  • Typical last frostApril 2950% chance of a frost after it
  • Typical first fall frostOctober 1250% chance of a frost before it
  • Frost-free season166 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Las Animas, COSpring: a frost after April 15 in 9 years out of 10, after April 29 in half of the years, after May 11 in 1 year out of 10. Fall: the first frost comes before October 2 in 1 year out of 10, before October 12 in half of the years, before October 23 in 9 years out of 10. Typical frost-free season: 166 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 29First frost ~Oct 12Frost season at Las Animas, COSpring: a frost after April 15 in 9 years out of 10, after April 29 in half of the years, after May 11 in 1 year out of 10. Fall: the first frost comes before October 2 in 1 year out of 10, before October 12 in half of the years, before October 23 in 9 years out of 10. Typical frost-free season: 166 days.JFMAMJJASONDLast frost ~Apr 29First 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 30 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 11October 2
50% (typical)April 29October 12
90% (likely)April 15October 23
Frost-free season (32°F, 50% chance)
166 days
Hard frost (28°F), last in spring, 50% chance after
April 18
Hard frost (28°F), first in fall, 50% chance before
October 21

The last 15 years (2006–2020 normals)

Typical last frost May 1 (2 days later than the 30-year normal), typical first fall frost October 15 (3 days later). Frost-free season 166 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 Las Animas: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 11, 20% May 7, 30% May 4, 40% May 1, 50% April 29, 60% April 26, 70% April 22, 80% April 19, 90% April 15. Observed last spring frost in recent years: 2021 May 6, 2022 April 18, 2023 April 27, 2024 April 21, 2025 April 21, 2026 May 7.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 11Apr 29Apr 152021: May 62022: April 182023: April 272024: April 212025: April 212026: May 7Fall at Las Animas: chance of a frost before this dateFall, chance of a frost before the date: 10% October 2, 20% October 5, 30% October 6, 40% October 9, 50% October 12, 60% October 14, 70% October 17, 80% October 19, 90% October 23. Observed first fall frost in recent years: 2021 October 13, 2022 October 13, 2023 October 8, 2024 October 31, 2025 October 19.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 2Oct 12Oct 232021: October 132022: October 132023: October 82024: October 312025: 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 6October 13
2022April 18October 13
2023April 27October 8
2024April 21October 31
2025April 21October 19
2026May 7season not over yet

What these dates mean

The cautious spring date in Las Animas is May 11, when there is only a 10 % chance of a light frost later; this date lets a gardener plan to set out tender crops with a low risk of frost damage.

The 50 % date is April 29, meaning the chance of a light frost later is exactly even, while the 90 % chance on April 15 makes an earlier planting a gamble. In the fall the cautious date is October 2, with a 10 % chance of a light frost earlier, and the 50 % date is October 12, indicating an even odds of frost before that point; the 90 % chance on October 23 makes a later harvest risky. The 50 % dates for hard frost are April 18 and October 21. A hard frost at 28 °F is more damaging than a light frost at 32 °F because it reaches temperatures that can kill plant tissue.

How to read the probabilities

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

  • Spring: "10% after May 11" 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 October 2" 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 Las Animas, CONumbered nearest stations: 1 — La Junta, CO — 16 mi; 2 — Lamar, CO — 32 mi; 3 — Eads, CO — 37 mi; 4 — Kim 15 NNE, CO — 43 mi; 5 — Tacony, CO — 50 mi.KS25 mi · 40 km1. La Junta, CO — 16 mi12. Lamar, CO — 32 mi23. Eads, CO — 37 mi34. Kim 15 NNE, CO — 43 mi45. Tacony, CO — 50 mi5
  1. La Junta, CO 16 mi (26 km)
  2. Lamar, CO 32 mi (51 km)
  3. Eads, CO 37 mi (60 km)
  4. Kim 15 NNE, CO 43 mi (68 km)
  5. Tacony, CO 50 mi (80 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: 38.0636, -103.2153.