U.S. Frost Dates by Weather Station

NOAA station USC00356213 · Oregon

Frost Dates near Oakridge, OR

NOAA weather station Oakridge Fish Hatchery (USC00356213), Oregon · elevation 1275 ft (389 m) · hardiness zone 8b*

Oakridge is the nearest town to the station (0.9 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 11only 1 spring in 10 still has a frost later
  • Typical last frostApril 2450% chance of a frost after it
  • Typical first fall frostOctober 2450% chance of a frost before it
  • Frost-free season183 daystypical year, 32°F
  • Hardiness zone8bcalculated*

The year at a glance

Frost season near Oakridge, ORSpring: a frost after March 31 in 9 years out of 10, after April 24 in half of the years, after May 11 in 1 year out of 10. Fall: the first frost comes before October 2 in 1 year out of 10, before October 24 in half of the years, before November 13 in 9 years out of 10. Typical frost-free season: 183 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 24First frost ~Oct 24Frost season near Oakridge, ORSpring: a frost after March 31 in 9 years out of 10, after April 24 in half of the years, after May 11 in 1 year out of 10. Fall: the first frost comes before October 2 in 1 year out of 10, before October 24 in half of the years, before November 13 in 9 years out of 10. Typical frost-free season: 183 days.JFMAMJJASONDLast frost ~Apr 24First frost ~Oct 24
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 11October 2
50% (typical)April 24October 24
90% (likely)March 31November 13
Frost-free season (32°F, 50% chance)
183 days
Hard frost (28°F), last in spring, 50% chance after
March 22
Hard frost (28°F), first in fall, 50% chance before
November 13

The last 15 years (2006–2020 normals)

Typical last frost April 28 (4 days later than the 30-year normal), typical first fall frost October 24. Frost-free season 179 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 Oakridge: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 11, 20% May 5, 30% May 1, 40% April 29, 50% April 24, 60% April 19, 70% April 13, 80% April 6, 90% March 31. Observed last spring frost in recent years: 2021 April 16, 2022 April 18, 2023 April 19, 2025 April 23, 2026 April 18.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 11Apr 24Mar 312021: April 162022: April 182023: April 192025: April 232026: April 18Fall near Oakridge: chance of a frost before this dateFall, chance of a frost before the date: 10% October 2, 20% October 10, 30% October 16, 40% October 20, 50% October 24, 60% October 27, 70% October 31, 80% November 5, 90% November 13. Observed first fall frost in recent years: 2021 November 8, 2022 November 11, 2023 October 28, 2024 October 25, 2025 November 22.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 2Oct 24Nov 132021: November 82022: November 112023: October 282024: October 252025: November 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
2021April 16November 8
2022April 18November 11
2023April 19October 28
2024incomplete recordOctober 25
2025April 23November 22
2026April 18season not over yet

What these dates mean

Setting out tender crops on March 31 in the Oakridge area is a gamble, because there is a 90% chance of a light frost occurring later. The cautious spring date for tender crops is May 11, when only a 10% chance of a later frost remains.

The 50% dates, April 24 for spring and October 24 for fall, each mark the point where the probability of a light frost is 50%. The 28°F 50% dates are March 22 and November 13, marking the median timing of hard frosts. A hard frost at 28°F can damage plants that would otherwise survive a light frost at 32°F.

The cautious fall date for finishing tender crops is October 2, when only a 10% chance of an earlier light frost exists. Over 29 years of record, the interval between the two 32°F 50% dates is 183 days.

How to read the probabilities

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

  • Spring: "10% after May 11" 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 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 Oakridge, ORNumbered nearest stations: 1 — near Lowell, OR — 20 mi; 2 — Dorena, OR — 26 mi; 3 — Leaburg, OR — 28 mi; 4 — Cottage Grove, OR — 29 mi; 5 — Toketee Falls, OR — 32 mi.25 mi · 40 km1. near Lowell, OR — 20 mi12. Dorena, OR — 26 mi23. Leaburg, OR — 28 mi34. Cottage Grove, OR — 29 mi45. Toketee Falls, OR — 32 mi5
  1. near Lowell, OR 20 mi (32 km)
  2. Dorena, OR 26 mi (42 km)
  3. Leaburg, OR 28 mi (44 km)
  4. Cottage Grove, OR 29 mi (47 km)
  5. Toketee Falls, OR 32 mi (52 km)

Sources

* Hardiness zone 8b: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 43.7428, -122.4433.