U.S. Frost Dates by Weather Station

NOAA station USC00051294 · Colorado

Frost Dates for Canon City, CO

NOAA weather station Canon City (USC00051294), Colorado · elevation 5378 ft (1639 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 18only 1 spring in 10 still has a frost later
  • Typical last frostMay 450% chance of a frost after it
  • Typical first fall frostOctober 750% chance of a frost before it
  • Frost-free season153 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Canon City, COSpring: a frost after April 24 in 9 years out of 10, after May 4 in half of the years, after May 18 in 1 year out of 10. Fall: the first frost comes before September 25 in 1 year out of 10, before October 7 in half of the years, before October 19 in 9 years out of 10. Typical frost-free season: 153 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 4First frost ~Oct 7Frost season at Canon City, COSpring: a frost after April 24 in 9 years out of 10, after May 4 in half of the years, after May 18 in 1 year out of 10. Fall: the first frost comes before September 25 in 1 year out of 10, before October 7 in half of the years, before October 19 in 9 years out of 10. Typical frost-free season: 153 days.JFMAMJJASONDLast frost ~May 4First frost ~Oct 7
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 25 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 18September 25
50% (typical)May 4October 7
90% (likely)April 24October 19
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 17

The last 15 years (2006–2020 normals)

Typical last frost May 8 (4 days later than the 30-year normal), typical first fall frost October 11 (4 days later). Frost-free season 154 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 Canon City: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 18, 20% May 13, 30% May 9, 40% May 6, 50% May 4, 60% May 2, 70% April 30, 80% April 28, 90% April 24. Observed last spring frost in recent years: 2021 April 23, 2022 May 22, 2023 April 26, 2024 May 9, 2025 April 29, 2026 May 7.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 18May 4Apr 242021: April 232022: May 222023: April 262024: May 92025: April 292026: May 7Fall at Canon City: chance of a frost before this dateFall, chance of a frost before the date: 10% September 25, 20% September 29, 30% October 2, 40% October 4, 50% October 7, 60% October 10, 70% October 12, 80% October 15, 90% October 19. Observed first fall frost in recent years: 2021 October 12, 2022 October 13, 2023 October 13, 2024 October 16, 2025 October 29.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 25Oct 7Oct 192021: October 122022: October 132023: October 132024: October 162025: October 29
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 12
2022May 22October 13
2023April 26October 13
2024May 9October 16
2025April 29October 29
2026May 7season not over yet

What these dates mean

Setting out tender crops on the early spring date of April 24 in Canon City carries a 90% chance that a light frost will still occur, making it a gamble for growers who need frost-free conditions.

The cautious spring date for tender crops is May 18, when only a 10% chance of a light frost remains, and the cautious fall date is September 25, with a 10% chance that a light frost has already arrived. The 50% date is April 26, indicating a 50% chance of a hard frost later than this date, and the 50% date is October 17, indicating a 50% chance of a hard frost earlier than this date.

Hard frost at 28 °F can damage plants that survive a light frost at 32 °F, so it matters more.

How to read the probabilities

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

  • Spring: "10% after May 18" 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 25" 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 Canon City, CONumbered nearest stations: 1 — Westcliffe, CO — 26 mi; 2 — Lake George 8 SW, CO — 34 mi; 3 — Colorado Springs, CO — 38 mi; 4 — Pueblo, CO — 41 mi; 5 — Sheep Mountain, CO — 51 mi.CO25 mi · 40 km1. Westcliffe, CO — 26 mi12. Lake George 8 SW, CO — 34 mi23. Colorado Springs, CO — 38 mi34. Pueblo, CO — 41 mi45. Sheep Mountain, CO — 51 mi5
  1. Westcliffe, CO 26 mi (42 km)
  2. Lake George 8 SW, CO 34 mi (54 km)
  3. Colorado Springs, CO 38 mi (61 km)
  4. Pueblo, CO 41 mi (66 km)
  5. Sheep Mountain, CO 51 mi (83 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: 38.46, -105.2256.