U.S. Frost Dates by Weather Station

NOAA station USC00050109 · Colorado

Frost Dates near Akron, CO

NOAA weather station Akron 4 E (USC00050109), Colorado · elevation 4542 ft (1384 m) · hardiness zone 5b*

Akron is the nearest town to the station (3.9 mi away) in GeoNames (CC BY 4.0). The dates below are measured at the station, not in the town itself.

  • Lower-risk planting dateafter May 22only 1 spring in 10 still has a frost later
  • Typical last frostMay 850% chance of a frost after it
  • Typical first fall frostOctober 650% chance of a frost before it
  • Frost-free season149 daystypical year, 32°F
  • Hardiness zone5bcalculated*

The year at a glance

Frost season near Akron, COSpring: a frost after April 27 in 9 years out of 10, after May 8 in half of the years, after May 22 in 1 year out of 10. Fall: the first frost comes before September 25 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: 149 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 8First frost ~Oct 6Frost season near Akron, COSpring: a frost after April 27 in 9 years out of 10, after May 8 in half of the years, after May 22 in 1 year out of 10. Fall: the first frost comes before September 25 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: 149 days.JFMAMJJASONDLast frost ~May 8First 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 22September 25
50% (typical)May 8October 6
90% (likely)April 27October 17
Frost-free season (32°F, 50% chance)
149 days
Hard frost (28°F), last in spring, 50% chance after
April 30
Hard frost (28°F), first in fall, 50% chance before
October 15

The last 15 years (2006–2020 normals)

Typical last frost May 9 (1 day later than the 30-year normal), typical first fall frost October 8 (2 days later). Frost-free season 151 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 near Akron: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 22, 20% May 16, 30% May 14, 40% May 11, 50% May 8, 60% May 6, 70% May 3, 80% May 1, 90% April 27. Observed last spring frost in recent years: 2021 May 12, 2022 May 3, 2023 May 1, 2024 May 7, 2025 April 30, 2026 May 6.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 22May 8Apr 272021: May 122022: May 32023: May 12024: May 72025: April 302026: May 6Fall near Akron: chance of a frost before this dateFall, chance of a frost before the date: 10% September 25, 20% September 29, 30% October 1, 40% October 4, 50% October 6, 60% October 8, 70% October 11, 80% October 13, 90% October 17. Observed first fall frost in recent years: 2021 October 14, 2022 October 17, 2023 October 7, 2024 October 14, 2025 October 19.Fall: first frostChance of a frost before this date10%50%90%Oct 1Sep 25Oct 6Oct 172021: October 142022: October 172023: October 72024: October 142025: 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 12October 14
2022May 3October 17
2023May 1October 7
2024May 7October 14
2025April 30October 19
2026May 6season not over yet

What these dates mean

Setting out tender crops on April 27 in the Akron area carries a gamble, because there is a 90 % chance that a light frost will occur later in the season. A more cautious approach waits until May 22, when only a 10 % chance remains for a frost after that date.

For the autumn harvest, counting on tender crops as late as October 17 is also a gamble, reflecting a 90 % chance that a light frost will have arrived earlier. The prudent cut-off is September 25, which has just a 10 % chance of a frost occurring before it. The 50 % dates—May 8 in spring and October 6 in fall—mark the median point where the odds of a light frost are equal; they serve only as reference markers, not as frost dates.

Hard frosts at 28 °F are noted by the 50 % dates April 30 and October 15, and they matter more than light frosts because temperatures that low can damage or kill plants that survive the milder 32 °F events.

How to read the probabilities

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

  • Spring: "10% after May 22" 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 Akron, CONumbered nearest stations: 1 — Akron Washington County Airport, CO — 4 mi; 2 — Yuma, CO — 22 mi; 3 — Leroy, CO — 26 mi; 4 — Joes, CO — 42 mi; 5 — Wray, CO — 50 mi.NEKS25 mi · 40 km1. Akron Washington County Airport, CO — 4 mi12. Yuma, CO — 22 mi23. Leroy, CO — 26 mi34. Joes, CO — 42 mi45. Wray, CO — 50 mi5
  1. Akron Washington County Airport, CO 4 mi (7 km)
  2. Yuma, CO 22 mi (36 km)
  3. Leroy, CO 26 mi (42 km)
  4. Joes, CO 42 mi (68 km)
  5. Wray, CO 50 mi (80 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: 40.155, -103.1417.