U.S. Frost Dates by Weather Station

NOAA station USC00350501 · Oregon

Frost Dates for Barnes Station, OR

NOAA weather station Barnes Station (USC00350501), Oregon · elevation 3970 ft (1210 m) · hardiness zone 6a*

  • Lower-risk planting dateafter June 25only 1 spring in 10 still has a frost later
  • Typical last frostJune 250% chance of a frost after it
  • Typical first fall frostSeptember 1750% chance of a frost before it
  • Frost-free season104 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Barnes Station, ORSpring: a frost after May 13 in 9 years out of 10, after June 2 in half of the years, after June 25 in 1 year out of 10. Fall: the first frost comes before August 30 in 1 year out of 10, before September 17 in half of the years, before October 1 in 9 years out of 10. Typical frost-free season: 104 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Jun 2First frost ~Sep 17Frost season at Barnes Station, ORSpring: a frost after May 13 in 9 years out of 10, after June 2 in half of the years, after June 25 in 1 year out of 10. Fall: the first frost comes before August 30 in 1 year out of 10, before September 17 in half of the years, before October 1 in 9 years out of 10. Typical frost-free season: 104 days.JFMAMJJASONDLast frost ~Jun 2First frost ~Sep 17
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 29 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)June 25August 30
50% (typical)June 2September 17
90% (likely)May 13October 1
Frost-free season (32°F, 50% chance)
104 days
Hard frost (28°F), last in spring, 50% chance after
May 12
Hard frost (28°F), first in fall, 50% chance before
September 30

The last 15 years (2006–2020 normals)

Typical last frost May 28 (5 days earlier than the 30-year normal), typical first fall frost September 19 (2 days later). Frost-free season 115 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 Barnes Station: chance of a frost after this dateSpring, chance of a frost after the date: 10% June 25, 20% June 17, 30% June 12, 40% June 7, 50% June 2, 60% May 29, 70% May 24, 80% May 19, 90% May 13. Observed last spring frost in recent years: 2021 June 7, 2022 May 20, 2023 June 20.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1Jul 1Jun 25Jun 2May 132021: June 72022: May 202023: June 20Fall at Barnes Station: chance of a frost before this dateFall, chance of a frost before the date: 10% August 30, 20% September 5, 30% September 9, 40% September 14, 50% September 17, 60% September 20, 70% September 23, 80% September 27, 90% October 1. Observed first fall frost in recent years: 2021 September 16, 2022 October 9, 2023 September 22.Fall: first frostChance of a frost before this date10%50%90%Sep 1Oct 1Aug 30Sep 17Oct 12021: September 162022: October 92023: September 22
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
2021June 7September 16
2022May 20October 9
2023June 20September 22
2024no datano data
2025no datano data
2026no dataseason not over yet

What these dates mean

Setting out tender crops on May 13 at Barnes Station is a gamble, because there is a 90% chance of a light frost occurring later. A more cautious plan would wait until June 25, when the chance of a later frost has dropped to 10%.

The 50% spring date is June 2, meaning a gardener has an even chance of a light frost occurring after that day; the 50% fall date is September 17, giving an even chance of a light frost occurring earlier. To finish harvesting tender crops with low risk, August 30 is used, as only a 10% chance of frost has arrived earlier. Counting on crops through October 1 carries a 90% chance of frost having begun. Hard frosts at 28 °F are more damaging than light frosts at 32 °F, so the median hard-frost dates of May 12 in spring and September 30 in fall are important reference points.

How to read the probabilities

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

  • Spring: "10% after June 25" 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 August 30" 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 Barnes Station, ORNumbered nearest stations: 1 — near Redmond, OR — 51 mi; 2 — Burns, OR — 67 mi; 3 — near Warm Springs, OR — 74 mi; 4 — near La Pine, OR — 76 mi; 5 — Marion Forks Fish Hatchery, OR — 97 mi.OR25 mi · 40 km1. near Redmond, OR — 51 mi12. Burns, OR — 67 mi23. near Warm Springs, OR — 74 mi34. near La Pine, OR — 76 mi45. Marion Forks Fish Hatchery, OR — 97 mi5
  1. near Redmond, OR 51 mi (81 km)
  2. Burns, OR 67 mi (108 km)
  3. near Warm Springs, OR 74 mi (120 km)
  4. near La Pine, OR 76 mi (122 km)
  5. Marion Forks Fish Hatchery, OR 97 mi (157 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: 43.9456, -120.2169.