U.S. Frost Dates by Weather Station

NOAA station USC00054380 · Colorado

Frost Dates for Joes, CO

NOAA weather station Joes (USC00054380), Colorado · elevation 4275 ft (1303 m) · hardiness zone 5b*

  • Lower-risk planting dateafter May 15only 1 spring in 10 still has a frost later
  • Typical last frostMay 350% chance of a frost after it
  • Typical first fall frostOctober 950% chance of a frost before it
  • Frost-free season158 daystypical year, 32°F
  • Hardiness zone5bcalculated*

The year at a glance

Frost season at Joes, COSpring: a frost after April 21 in 9 years out of 10, after May 3 in half of the years, after May 15 in 1 year out of 10. Fall: the first frost comes before September 29 in 1 year out of 10, before October 9 in half of the years, before October 19 in 9 years out of 10. Typical frost-free season: 158 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 3First frost ~Oct 9Frost season at Joes, COSpring: a frost after April 21 in 9 years out of 10, after May 3 in half of the years, after May 15 in 1 year out of 10. Fall: the first frost comes before September 29 in 1 year out of 10, before October 9 in half of the years, before October 19 in 9 years out of 10. Typical frost-free season: 158 days.JFMAMJJASONDLast frost ~May 3First frost ~Oct 9
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.Today

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 15September 29
50% (typical)May 3October 9
90% (likely)April 21October 19
Frost-free season (32°F, 50% chance)
158 days
Hard frost (28°F), last in spring, 50% chance after
April 24
Hard frost (28°F), first in fall, 50% chance before
October 18

The last 15 years (2006–2020 normals)

Typical last frost May 4 (1 day later than the 30-year normal), typical first fall frost October 13 (4 days later). Frost-free season 159 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 Joes: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 15, 20% May 10, 30% May 7, 40% May 5, 50% May 3, 60% May 1, 70% April 29, 80% April 26, 90% April 21. Observed last spring frost in recent years: 2021 April 25, 2022 May 2.Spring: last frostChance of a frost after this date10%50%90%May 1May 15May 3Apr 212021: April 252022: May 2Fall at Joes: chance of a frost before this dateFall, chance of a frost before the date: 10% September 29, 20% October 2, 30% October 5, 40% October 7, 50% October 9, 60% October 12, 70% October 14, 80% October 16, 90% October 19. Observed first fall frost in recent years: 2021 October 14.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 29Oct 9Oct 192021: October 14
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 25October 14
2022May 2incomplete record
2023incomplete recordno data
2024no datano data
2025no datano data
2026no dataseason not over yet

What these dates mean

May 15, the cautious spring date with a 10 % chance of a light frost later, lets a gardener plan to set out tender crops with minimal risk. By contrast, April 21 carries a 90 % chance and would be a gamble for early planting, while the 50 % date is May 3, indicating an even odds of a light frost occurring.

The 50 % date is October 9, showing an even odds of a light frost occurring in the fall, and the cautious fall date is September 29 with a 10 % chance of a frost earlier. The hard-frost median dates are April 24 and October 18; a hard frost at 28 °F can damage plants more severely than a light frost at 32 °F.

How to read the probabilities

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

  • Spring: "10% after May 15" 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 29" 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 Joes, CONumbered nearest stations: 1 — Bonny Dam 2 NE, CO — 30 mi; 2 — Yuma, CO — 32 mi; 3 — Burlington, CO — 33 mi; 4 — Wray, CO — 39 mi; 5 — near Akron, CO — 42 mi.COKSNE25 mi · 40 km1. Bonny Dam 2 NE, CO — 30 mi12. Yuma, CO — 32 mi23. Burlington, CO — 33 mi34. Wray, CO — 39 mi45. near Akron, CO — 42 mi5
  1. Bonny Dam 2 NE, CO 30 mi (48 km)
  2. Yuma, CO 32 mi (52 km)
  3. Burlington, CO 33 mi (53 km)
  4. Wray, CO 39 mi (62 km)
  5. near Akron, CO 42 mi (68 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: 39.6553, -102.6805.