U.S. Frost Dates by Weather Station

NOAA station USW00024130 · Oregon

Frost Dates for Baker City, OR

NOAA weather station Baker City Municipal Airport (USW00024130), Oregon · elevation 3361 ft (1024 m) · hardiness zone 6a*

  • Lower-risk planting dateafter June 16only 1 spring in 10 still has a frost later
  • Typical last frostMay 2550% chance of a frost after it
  • Typical first fall frostSeptember 1550% chance of a frost before it
  • Frost-free season111 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Baker City, ORSpring: a frost after May 9 in 9 years out of 10, after May 25 in half of the years, after June 16 in 1 year out of 10. Fall: the first frost comes before September 2 in 1 year out of 10, before September 15 in half of the years, before October 1 in 9 years out of 10. Typical frost-free season: 111 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 25First frost ~Sep 15Frost season at Baker City, ORSpring: a frost after May 9 in 9 years out of 10, after May 25 in half of the years, after June 16 in 1 year out of 10. Fall: the first frost comes before September 2 in 1 year out of 10, before September 15 in half of the years, before October 1 in 9 years out of 10. Typical frost-free season: 111 days.JFMAMJJASONDLast frost ~May 25First frost ~Sep 15
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 28 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)June 16September 2
50% (typical)May 25September 15
90% (likely)May 9October 1
Frost-free season (32°F, 50% chance)
111 days
Hard frost (28°F), last in spring, 50% chance after
May 8
Hard frost (28°F), first in fall, 50% chance before
September 27

The last 15 years (2006–2020 normals)

Typical last frost May 19 (6 days earlier than the 30-year normal), typical first fall frost September 15. Frost-free season 118 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 Baker City: chance of a frost after this dateSpring, chance of a frost after the date: 10% June 16, 20% June 9, 30% June 4, 40% May 30, 50% May 25, 60% May 22, 70% May 17, 80% May 13, 90% May 9. Observed last spring frost in recent years: 2021 June 7, 2022 June 15, 2023 June 21, 2024 May 21, 2025 June 23, 2026 June 11.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1Jun 16May 25May 92021: June 72022: June 152023: June 212024: May 212025: June 232026: June 11Fall at Baker City: chance of a frost before this dateFall, chance of a frost before the date: 10% September 2, 20% September 6, 30% September 9, 40% September 12, 50% September 15, 60% September 18, 70% September 21, 80% September 24, 90% October 1. Observed first fall frost in recent years: 2021 August 24, 2022 September 9, 2023 September 20, 2024 August 29, 2025 September 23.Fall: first frostChance of a frost before this date10%50%90%Sep 1Oct 1Sep 2Sep 15Oct 12021: August 242022: September 92023: September 202024: August 292025: September 23
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 7August 24
2022June 15September 9
2023June 21September 20
2024May 21August 29
2025June 23September 23
2026June 11season not over yet

What these dates mean

June 16 is the cautious spring light-frost date for Baker City; with only a 10 % chance of a frost later, a gardener can plan to set out tender crops after this point. The counterpart in fall is September 2, the cautious date when there is just a 10 % chance that a light frost has already arrived, so harvesting tender crops can be finished by then.

The 50 % light-frost dates are May 25 in spring and September 15 in fall; each marks the median point where a frost is just as likely to occur as not, but they are not frost events themselves. The 28 °F hard-frost median dates are May 8 and September 27, and hard frosts are more consequential because they can kill or severely damage plants that survive a light frost.

How to read the probabilities

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

  • Spring: "10% after June 16" 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 2" 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 Baker City, ORNumbered nearest stations: 1 — Halfway, OR — 34 mi; 2 — La Grande, OR — 35 mi; 3 — Cambridge, ID — 59 mi; 4 — Pilot Rock, OR — 66 mi; 5 — Payette, ID — 68 mi.OR25 mi · 40 km1. Halfway, OR — 34 mi12. La Grande, OR — 35 mi23. Cambridge, ID — 59 mi34. Pilot Rock, OR — 66 mi45. Payette, ID — 68 mi5
  1. Halfway, OR 34 mi (55 km)
  2. La Grande, OR 35 mi (57 km)
  3. Cambridge, ID 59 mi (94 km)
  4. Pilot Rock, OR 66 mi (106 km)
  5. Payette, ID 68 mi (110 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: 44.8428, -117.8086.