U.S. Frost Dates by Weather Station

NOAA station USC00058157 · Colorado

Frost Dates for Tacony, CO

NOAA weather station Tacony 13 SE (USC00058157), Colorado · elevation 4882 ft (1488 m) · hardiness zone 5b*

  • Lower-risk planting dateafter May 16only 1 spring in 10 still has a frost later
  • Typical last frostMay 550% chance of a frost after it
  • Typical first fall frostOctober 650% chance of a frost before it
  • Frost-free season153 daystypical year, 32°F
  • Hardiness zone5bcalculated*

The year at a glance

Frost season at Tacony, COSpring: a frost after April 23 in 9 years out of 10, after May 5 in half of the years, after May 16 in 1 year out of 10. Fall: the first frost comes before September 26 in 1 year out of 10, before October 6 in half of the years, before October 17 in 9 years out of 10. Typical frost-free season: 153 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 5First frost ~Oct 6Frost season at Tacony, COSpring: a frost after April 23 in 9 years out of 10, after May 5 in half of the years, after May 16 in 1 year out of 10. Fall: the first frost comes before September 26 in 1 year out of 10, before October 6 in half of the years, before October 17 in 9 years out of 10. Typical frost-free season: 153 days.JFMAMJJASONDLast frost ~May 5First frost ~Oct 6
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 16September 26
50% (typical)May 5October 6
90% (likely)April 23October 17
Frost-free season (32°F, 50% chance)
153 days
Hard frost (28°F), last in spring, 50% chance after
April 26
Hard frost (28°F), first in fall, 50% chance before
October 14

The last 15 years (2006–2020 normals)

Typical last frost May 7 (2 days later than the 30-year normal), typical first fall frost October 10 (4 days later). Frost-free season 153 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 Tacony: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 16, 20% May 12, 30% May 10, 40% May 8, 50% May 5, 60% May 3, 70% May 1, 80% April 28, 90% April 23. Observed last spring frost in recent years: 2021 May 11, 2022 May 21, 2023 April 29, 2024 May 8, 2025 May 17, 2026 May 7.Spring: last frostChance of a frost after this date10%50%90%May 1May 16May 5Apr 232021: May 112022: May 212023: April 292024: May 82025: May 172026: May 7Fall at Tacony: chance of a frost before this dateFall, chance of a frost before the date: 10% September 26, 20% September 30, 30% October 1, 40% October 4, 50% October 6, 60% October 8, 70% October 11, 80% October 14, 90% October 17. Observed first fall frost in recent years: 2021 October 14, 2022 October 17, 2023 October 14, 2024 October 16, 2025 October 19.Fall: first frostChance of a frost before this date10%50%90%Oct 1Sep 26Oct 6Oct 172021: October 142022: October 172023: October 142024: October 162025: 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 11October 14
2022May 21October 17
2023April 29October 14
2024May 8October 16
2025May 17October 19
2026May 7season not over yet

What these dates mean

The 153 days between the 50% dates in Tacony, Colorado, frame the period when light frosts are equally likely to have occurred or not. The 32°F 50% dates are May 5 and October 6, and they are not frost dates. The hard-frost 50% dates are April 26 and October 14.

For a cautious planting schedule, the spring light-frost date with only a 10% chance of a later frost is May 16, while the fall light-frost date with only a 10% chance of an earlier frost is September 26. These dates give the lowest risk for setting out or finishing tender crops. A hard frost at 28 °F is more consequential than a light frost at 32 °F because it can damage plant tissue that survives a milder freeze.

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 26" 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 Tacony, CONumbered nearest stations: 1 — Pueblo, CO — 24 mi; 2 — La Junta, CO — 36 mi; 3 — Colorado Springs, CO — 47 mi; 4 — Las Animas, CO — 50 mi; 5 — near Limon, CO — 61 mi.CO25 mi · 40 km1. Pueblo, CO — 24 mi12. La Junta, CO — 36 mi23. Colorado Springs, CO — 47 mi34. Las Animas, CO — 50 mi45. near Limon, CO — 61 mi5
  1. Pueblo, CO 24 mi (39 km)
  2. La Junta, CO 36 mi (58 km)
  3. Colorado Springs, CO 47 mi (76 km)
  4. Las Animas, CO 50 mi (80 km)
  5. near Limon, CO 61 mi (99 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: 38.3422, -104.0567.