U.S. Frost Dates by Weather Station

NOAA station USW00023066 · Colorado

Frost Dates for Grand Junction (Walker Field), CO

NOAA weather station Grand Junction Walker Field (USW00023066), Colorado · elevation 4858 ft (1481 m) · hardiness zone 7a*

  • Lower-risk planting dateafter May 14only 1 spring in 10 still has a frost later
  • Typical last frostApril 2850% chance of a frost after it
  • Typical first fall frostOctober 1650% chance of a frost before it
  • Frost-free season171 daystypical year, 32°F
  • Hardiness zone7acalculated*

The year at a glance

Frost season at Grand Junction (Walker Field), COSpring: a frost after April 11 in 9 years out of 10, after April 28 in half of the years, after May 14 in 1 year out of 10. Fall: the first frost comes before October 3 in 1 year out of 10, before October 16 in half of the years, before October 29 in 9 years out of 10. Typical frost-free season: 171 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 28First frost ~Oct 16Frost season at Grand Junction (Walker Field), COSpring: a frost after April 11 in 9 years out of 10, after April 28 in half of the years, after May 14 in 1 year out of 10. Fall: the first frost comes before October 3 in 1 year out of 10, before October 16 in half of the years, before October 29 in 9 years out of 10. Typical frost-free season: 171 days.JFMAMJJASONDLast frost ~Apr 28First frost ~Oct 16
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 29 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 14October 3
50% (typical)April 28October 16
90% (likely)April 11October 29
Frost-free season (32°F, 50% chance)
171 days
Hard frost (28°F), last in spring, 50% chance after
April 13
Hard frost (28°F), first in fall, 50% chance before
October 27

The last 15 years (2006–2020 normals)

Typical last frost April 27 (1 day earlier than the 30-year normal), typical first fall frost October 15 (1 day earlier). Frost-free season 170 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 Grand Junction (Walker Field): chance of a frost after this dateSpring, chance of a frost after the date: 10% May 14, 20% May 7, 30% May 3, 40% May 1, 50% April 28, 60% April 25, 70% April 21, 80% April 16, 90% April 11. Observed last spring frost in recent years: 2021 April 21, 2022 May 21, 2023 April 21, 2024 May 8, 2025 April 20, 2026 April 19.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 14Apr 28Apr 112021: April 212022: May 212023: April 212024: May 82025: April 202026: April 19Fall at Grand Junction (Walker Field): chance of a frost before this dateFall, chance of a frost before the date: 10% October 3, 20% October 7, 30% October 10, 40% October 14, 50% October 16, 60% October 19, 70% October 22, 80% October 25, 90% October 29. Observed first fall frost in recent years: 2021 October 15, 2022 October 24, 2023 October 29, 2024 November 1, 2025 October 28.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 3Oct 16Oct 292021: October 152022: October 242023: October 292024: November 12025: October 28
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 21October 15
2022May 21October 24
2023April 21October 29
2024May 8November 1
2025April 20October 28
2026April 19season not over yet

What these dates mean

Setting out tender crops on April 11 in Grand Junction (Walker Field) carries a 90% chance of a frost later, making it a gamble. The cautious alternative is May 14, when only a 10% chance of a later frost remains, offering a much lower risk for tender varieties.

The 50% spring date is April 28; it carries a 50% chance that a frost will occur later. The 50% fall date is October 16; it carries a 50% chance that a frost will occur earlier. A hard frost, marked by the 28°F median dates of April 13 and October 27, can damage plants more severely than a light frost. For a cautious fall plan, October 3 provides only a 10% chance that a frost has arrived earlier.

How to read the probabilities

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

  • Spring: "10% after May 14" 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 3" 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 Grand Junction (Walker Field), CONumbered nearest stations: 1 — Grand Junction, CO — 7 mi; 2 — Palisade, CO — 10 mi; 3 — Altenbern, CO — 27 mi; 4 — Paonia, CO — 53 mi; 5 — Moab, UT — 67 mi.UT25 mi · 40 km1. Grand Junction, CO — 7 mi12. Palisade, CO — 10 mi23. Altenbern, CO — 27 mi34. Paonia, CO — 53 mi45. Moab, UT — 67 mi5
  1. Grand Junction, CO 7 mi (12 km)
  2. Palisade, CO 10 mi (16 km)
  3. Altenbern, CO 27 mi (43 km)
  4. Paonia, CO 53 mi (85 km)
  5. Moab, UT 67 mi (107 km)

Sources

* Hardiness zone 7a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 39.1342, -108.54.