U.S. Frost Dates by Weather Station

NOAA station USC00357331 · Oregon

Frost Dates near Roseburg, OR

NOAA weather station Roseburg Kqen (USC00357331), Oregon · elevation 425 ft (130 m) · hardiness zone 9a*

Roseburg is the nearest town to the station (1.2 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 April 16only 1 spring in 10 still has a frost later
  • Typical last frostMarch 2350% chance of a frost after it
  • Typical first fall frostNovember 1850% chance of a frost before it
  • Frost-free season237 daystypical year, 32°F
  • Hardiness zone9acalculated*

The year at a glance

Frost season near Roseburg, ORSpring: a frost after February 25 in 9 years out of 10, after March 23 in half of the years, after April 16 in 1 year out of 10. Fall: the first frost comes before October 24 in 1 year out of 10, before November 18 in half of the years, before December 17 in 9 years out of 10. Typical frost-free season: 237 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Mar 23First frost ~Nov 18Frost season near Roseburg, ORSpring: a frost after February 25 in 9 years out of 10, after March 23 in half of the years, after April 16 in 1 year out of 10. Fall: the first frost comes before October 24 in 1 year out of 10, before November 18 in half of the years, before December 17 in 9 years out of 10. Typical frost-free season: 237 days.JFMAMJJASONDLast frost ~Mar 23First frost ~Nov 18
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 26 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)April 16October 24
50% (typical)March 23November 18
90% (likely)February 25December 17
Frost-free season (32°F, 50% chance)
237 days
Hard frost (28°F), last in spring, 50% chance after
February 20
Hard frost (28°F), first in fall, 50% chance before
December 11

The last 15 years (2006–2020 normals)

Typical last frost March 26 (3 days later than the 30-year normal), typical first fall frost November 20 (2 days later). Frost-free season 242 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 Roseburg: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 16, 20% April 7, 30% April 1, 40% March 28, 50% March 23, 60% March 19, 70% March 13, 80% March 4, 90% February 25. Observed last spring frost in recent years: 2022 April 17.Spring: last frostChance of a frost after this date10%50%90%Mar 1Apr 1Apr 16Mar 23Feb 252022: April 17Fall near Roseburg: chance of a frost before this dateFall, chance of a frost before the date: 10% October 24, 20% October 31, 30% November 5, 40% November 11, 50% November 18, 60% November 24, 70% November 30, 80% December 6, 90% December 17. Observed first fall frost in recent years: 2023 October 29.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Oct 24Nov 18Dec 172023: October 29
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
2021no dataincomplete record
2022April 17incomplete record
2023incomplete recordOctober 29
2024incomplete recordno data
2025no datano data
2026no dataseason not over yet

What these dates mean

The 237 days between the 32 °F 50% dates of March 23 and November 18 mark the interval in which a 50 % chance of a light frost frames the growing season, and gardeners can schedule planting and harvest inside that span. The 50% dates themselves are median points; there is a 50 % chance of a frost later than March 23 in spring and a 50 % chance of a frost earlier than November 18 in fall. For a cautious plan the spring light-frost cautious date is April 16, while the fall cautious date is October 24. The median hard-frost dates are February 20 and December 11, indicating a 50 % chance of a 28 °F event. The record spans 26 years, providing the basis for these probabilities. Hard frost at 28 °F is more destructive than light frost at 32 °F because it can damage plant tissue that survives 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 April 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 October 24" 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 Roseburg, ORNumbered nearest stations: 1 — Riddle, OR — 18 mi; 2 — Drain, OR — 31 mi; 3 — near Coquille, OR — 42 mi; 4 — Sexton Summit, OR — 42 mi; 5 — Cottage Grove, OR — 43 mi.OR25 mi · 40 km1. Riddle, OR — 18 mi12. Drain, OR — 31 mi23. near Coquille, OR — 42 mi34. Sexton Summit, OR — 42 mi45. Cottage Grove, OR — 43 mi5
  1. Riddle, OR 18 mi (29 km)
  2. Drain, OR 31 mi (50 km)
  3. near Coquille, OR 42 mi (68 km)
  4. Sexton Summit, OR 42 mi (68 km)
  5. Cottage Grove, OR 43 mi (70 km)

Sources

* Hardiness zone 9a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 43.2131, -123.3658.