U.S. Frost Dates by Weather Station

NOAA station USC00351862 · Oregon

Frost Dates near Corvallis, OR

NOAA weather station Corvallis State University (USC00351862), Oregon · elevation 225 ft (69 m) · hardiness zone 8b*

Corvallis is the nearest town to the station (6.0 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 8only 1 spring in 10 still has a frost later
  • Typical last frostApril 1750% chance of a frost after it
  • Typical first fall frostOctober 2850% chance of a frost before it
  • Frost-free season194 daystypical year, 32°F
  • Hardiness zone8bcalculated*

The year at a glance

Frost season near Corvallis, ORSpring: a frost after March 22 in 9 years out of 10, after April 17 in half of the years, after May 8 in 1 year out of 10. Fall: the first frost comes before October 5 in 1 year out of 10, before October 28 in half of the years, before November 19 in 9 years out of 10. Typical frost-free season: 194 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 17First frost ~Oct 28Frost season near Corvallis, ORSpring: a frost after March 22 in 9 years out of 10, after April 17 in half of the years, after May 8 in 1 year out of 10. Fall: the first frost comes before October 5 in 1 year out of 10, before October 28 in half of the years, before November 19 in 9 years out of 10. Typical frost-free season: 194 days.JFMAMJJASONDLast frost ~Apr 17First frost ~Oct 28
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 8October 5
50% (typical)April 17October 28
90% (likely)March 22November 19
Frost-free season (32°F, 50% chance)
194 days
Hard frost (28°F), last in spring, 50% chance after
March 1
Hard frost (28°F), first in fall, 50% chance before
November 17

The last 15 years (2006–2020 normals)

Typical last frost April 17 (same as the 30-year normal), typical first fall frost October 28. Frost-free season 196 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 Corvallis: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 8, 20% May 1, 30% April 27, 40% April 23, 50% April 17, 60% April 12, 70% April 6, 80% March 31, 90% March 22. Observed last spring frost in recent years: 2021 May 20, 2022 April 23, 2023 March 27, 2024 April 21, 2025 March 7.Spring: last frostChance of a frost after this date10%50%90%Mar 1Apr 1May 1May 8Apr 17Mar 222021: May 202022: April 232023: March 272024: April 212025: March 7Fall near Corvallis: chance of a frost before this dateFall, chance of a frost before the date: 10% October 5, 20% October 14, 30% October 20, 40% October 25, 50% October 28, 60% November 1, 70% November 4, 80% November 10, 90% November 19. Observed first fall frost in recent years: 2021 October 12, 2022 November 9, 2023 October 29, 2024 October 24.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Dec 1Oct 5Oct 28Nov 192021: October 122022: November 92023: October 292024: October 24
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 20October 12
2022April 23November 9
2023March 27October 29
2024April 21October 24
2025March 7no data
2026no dataseason not over yet

What these dates mean

May 8 is the cautious spring date for the Corvallis area, and it lets a gardener set out tender crops while keeping the chance of a light frost later to only ten percent. The median light-frost date in spring is April 17, which carries a fifty-percent chance of a light frost later, and planting before March 22 carries a ninety-percent chance of a light frost and is a gamble.

October 5 is the cautious fall date to finish harvesting tender crops, with only a ten-percent chance that a light frost has already arrived. The median light-frost date in fall is October 28, which carries a fifty-percent chance of a light frost earlier, while planting after November 19 would face a ninety-percent risk. A hard frost at 28 °F can damage plants that survive a 32 °F light frost, so the hard-frost median dates—March 1 in spring and November 17 in fall—provide the key thresholds for the harsher cold.

How to read the probabilities

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

  • Spring: "10% after May 8" 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 5" 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 Corvallis, ORNumbered nearest stations: 1 — Stayton, OR — 21 mi; 2 — Dallas, OR — 22 mi; 3 — Lacomb, OR — 23 mi; 4 — near Sweet Home, OR — 30 mi; 5 — Silverton, OR — 33 mi.25 mi · 40 km1. Stayton, OR — 21 mi12. Dallas, OR — 22 mi23. Lacomb, OR — 23 mi34. near Sweet Home, OR — 30 mi45. Silverton, OR — 33 mi5
  1. Stayton, OR 21 mi (34 km)
  2. Dallas, OR 22 mi (36 km)
  3. Lacomb, OR 23 mi (37 km)
  4. near Sweet Home, OR 30 mi (48 km)
  5. Silverton, 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: 44.6342, -123.19.