U.S. Frost Dates by Weather Station

NOAA station USW00024221 · Oregon

Frost Dates near Eugene, OR

NOAA weather station Eugene Mahlon Sweet Airport (USW00024221), Oregon · elevation 353 ft (108 m) · hardiness zone 8b*

Eugene is the nearest town to the station (8.5 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 9only 1 spring in 10 still has a frost later
  • Typical last frostApril 1150% chance of a frost after it
  • Typical first fall frostOctober 2350% chance of a frost before it
  • Frost-free season196 daystypical year, 32°F
  • Hardiness zone8bcalculated*

The year at a glance

Frost season near Eugene, ORSpring: a frost after March 15 in 9 years out of 10, after April 11 in half of the years, after May 9 in 1 year out of 10. Fall: the first frost comes before October 6 in 1 year out of 10, before October 23 in half of the years, before November 13 in 9 years out of 10. Typical frost-free season: 196 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 11First frost ~Oct 23Frost season near Eugene, ORSpring: a frost after March 15 in 9 years out of 10, after April 11 in half of the years, after May 9 in 1 year out of 10. Fall: the first frost comes before October 6 in 1 year out of 10, before October 23 in half of the years, before November 13 in 9 years out of 10. Typical frost-free season: 196 days.JFMAMJJASONDLast frost ~Apr 11First frost ~Oct 23
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 25 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 9October 6
50% (typical)April 11October 23
90% (likely)March 15November 13
Frost-free season (32°F, 50% chance)
196 days
Hard frost (28°F), last in spring, 50% chance after
March 3
Hard frost (28°F), first in fall, 50% chance before
November 11

The last 15 years (2006–2020 normals)

Typical last frost April 11 (same as the 30-year normal), typical first fall frost October 22 (1 day earlier). Frost-free season 197 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 Eugene: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 9, 20% April 30, 30% April 25, 40% April 17, 50% April 11, 60% April 3, 70% March 29, 80% March 23, 90% March 15. Observed last spring frost in recent years: 2021 April 11, 2022 April 17, 2023 March 27, 2024 April 18, 2025 March 7, 2026 April 17.Spring: last frostChance of a frost after this date10%50%90%Mar 1Apr 1May 1May 9Apr 11Mar 152021: April 112022: April 172023: March 272024: April 182025: March 72026: April 17Fall near Eugene: chance of a frost before this dateFall, chance of a frost before the date: 10% October 6, 20% October 11, 30% October 15, 40% October 19, 50% October 23, 60% October 27, 70% October 31, 80% November 5, 90% November 13. Observed first fall frost in recent years: 2021 October 12, 2022 November 9, 2023 October 28, 2024 October 24, 2025 October 15.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 6Oct 23Nov 132021: October 122022: November 92023: October 282024: October 242025: October 15
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 11October 12
2022April 17November 9
2023March 27October 28
2024April 18October 24
2025March 7October 15
2026April 17season not over yet

What these dates mean

May 9 is the cautious spring light-frost date for the Eugene area; on that day there is only a 10 % chance of a 32 °F frost later, so planting tender crops after May 9 gives a low risk of frost damage.

The 50% date is April 11 for spring and October 23 for fall; each marks the point where a light frost is equally likely to occur before or after, giving gardeners a mid-range reference for timing. The 50% hard-frost dates are March 3 in spring and November 11 in fall. October 6 is the cautious fall light-frost date, with only a 10 % chance that frost has arrived earlier, allowing harvests to be finished with minimal risk.

A hard frost at 28 °F can injure or kill plants that survive a 32 °F light frost, so the hard-frost dates signal a higher threat level.

How to read the probabilities

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

  • Spring: "10% after May 9" 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 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 Eugene, ORNumbered nearest stations: 1 — Cottage Grove, OR — 25 mi; 2 — Leaburg, OR — 26 mi; 3 — Dorena, OR — 27 mi; 4 — near Lowell, OR — 27 mi; 5 — Drain, OR — 33 mi.25 mi · 40 km1. Cottage Grove, OR — 25 mi12. Leaburg, OR — 26 mi23. Dorena, OR — 27 mi34. near Lowell, OR — 27 mi45. Drain, OR — 33 mi5
  1. Cottage Grove, OR 25 mi (40 km)
  2. Leaburg, OR 26 mi (43 km)
  3. Dorena, OR 27 mi (44 km)
  4. near Lowell, OR 27 mi (44 km)
  5. Drain, OR 33 mi (53 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: 44.1278, -123.2206.