U.S. Frost Dates by Weather Station

NOAA station USC00054742 · Colorado

Frost Dates for Lake George 8 SW, CO

NOAA weather station Lake George 8 SW (USC00054742), Colorado · elevation 8550 ft (2606 m) · hardiness zone 4b*

  • Lower-risk planting dateafter June 17only 1 spring in 10 still has a frost later
  • Typical last frostJune 250% chance of a frost after it
  • Typical first fall frostSeptember 1950% chance of a frost before it
  • Frost-free season108 daystypical year, 32°F
  • Hardiness zone4bcalculated*

The year at a glance

Frost season at Lake George 8 SW, COSpring: a frost after May 19 in 9 years out of 10, after June 2 in half of the years, after June 17 in 1 year out of 10. Fall: the first frost comes before September 6 in 1 year out of 10, before September 19 in half of the years, before September 30 in 9 years out of 10. Typical frost-free season: 108 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Jun 2First frost ~Sep 19Frost season at Lake George 8 SW, COSpring: a frost after May 19 in 9 years out of 10, after June 2 in half of the years, after June 17 in 1 year out of 10. Fall: the first frost comes before September 6 in 1 year out of 10, before September 19 in half of the years, before September 30 in 9 years out of 10. Typical frost-free season: 108 days.JFMAMJJASONDLast frost ~Jun 2First frost ~Sep 19
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 28 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)June 17September 6
50% (typical)June 2September 19
90% (likely)May 19September 30
Frost-free season (32°F, 50% chance)
108 days
Hard frost (28°F), last in spring, 50% chance after
May 19
Hard frost (28°F), first in fall, 50% chance before
September 29

The last 15 years (2006–2020 normals)

Typical last frost June 1 (1 day earlier than the 30-year normal), typical first fall frost September 25 (6 days later). Frost-free season 114 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 Lake George 8 SW: chance of a frost after this dateSpring, chance of a frost after the date: 10% June 17, 20% June 11, 30% June 7, 40% June 5, 50% June 2, 60% May 31, 70% May 29, 80% May 24, 90% May 19. Observed last spring frost in recent years: 2021 May 27, 2022 June 2, 2023 May 12, 2024 May 27, 2025 May 21, 2026 May 31.Spring: last frostChance of a frost after this date10%50%90%Jun 1Jul 1Jun 17Jun 2May 192021: May 272022: June 22023: May 122024: May 272025: May 212026: May 31Fall at Lake George 8 SW: chance of a frost before this dateFall, chance of a frost before the date: 10% September 6, 20% September 11, 30% September 15, 40% September 17, 50% September 19, 60% September 21, 70% September 24, 80% September 26, 90% September 30. Observed first fall frost in recent years: 2021 September 22, 2022 October 8, 2023 September 24, 2024 October 7, 2025 October 5.Fall: first frostChance of a frost before this date10%50%90%Sep 1Oct 1Sep 6Sep 19Sep 302021: September 222022: October 82023: September 242024: October 72025: October 5
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 27September 22
2022June 2October 8
2023May 12September 24
2024May 27October 7
2025May 21October 5
2026May 31season not over yet

What these dates mean

June 17 is the cautious spring date, with only a 10 % chance of a light frost later, so a gardener can plan to set out tender crops after that day with minimal risk. The 50 % date is June 2, which represents a 50 % chance of a frost later than this date. May 19 carries a 90 % chance of a frost later, making an early planting a gamble.

September 6 is the cautious fall date, providing a 10 % chance of a light frost earlier and marking a sensible point to finish harvesting tender crops. The 50 % date is September 19, indicating a 50 % chance of a frost earlier than this date. September 30 has a 90 % chance of a frost earlier, so relying on crops that late would be risky.

The 50 % hard-frost dates are May 19 in spring and September 29 in fall; a hard frost at 28 °F can damage plants that survive a light frost at 32 °F, making it a more critical threshold for protecting tender crops.

How to read the probabilities

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

  • Spring: "10% after June 17" 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 6" 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 Lake George 8 SW, CONumbered nearest stations: 1 — Canon City, CO — 34 mi; 2 — Bailey, CO — 34 mi; 3 — Buena Vista, CO — 36 mi; 4 — Grant, CO — 40 mi; 5 — Colorado Springs, CO — 43 mi.25 mi · 40 km1. Canon City, CO — 34 mi12. Bailey, CO — 34 mi23. Buena Vista, CO — 36 mi34. Grant, CO — 40 mi45. Colorado Springs, CO — 43 mi5
  1. Canon City, CO 34 mi (54 km)
  2. Bailey, CO 34 mi (55 km)
  3. Buena Vista, CO 36 mi (58 km)
  4. Grant, CO 40 mi (64 km)
  5. Colorado Springs, CO 43 mi (69 km)

Sources

* Hardiness zone 4b: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 38.9075, -105.4706.