U.S. Frost Dates by Weather Station

NOAA station USC00353770 · Oregon

Frost Dates near Sandy, OR

NOAA weather station Headworks Portland Water B (USC00353770), Oregon · elevation 748 ft (228 m) · hardiness zone 8b*

Sandy is the nearest town to the station (6.3 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 20only 1 spring in 10 still has a frost later
  • Typical last frostMarch 2750% chance of a frost after it
  • Typical first fall frostNovember 1850% chance of a frost before it
  • Frost-free season239 daystypical year, 32°F
  • Hardiness zone8bcalculated*

The year at a glance

Frost season near Sandy, ORSpring: a frost after February 26 in 9 years out of 10, after March 27 in half of the years, after April 20 in 1 year out of 10. Fall: the first frost comes before October 26 in 1 year out of 10, before November 18 in half of the years, before December 10 in 9 years out of 10. Typical frost-free season: 239 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Mar 27First frost ~Nov 18Frost season near Sandy, ORSpring: a frost after February 26 in 9 years out of 10, after March 27 in half of the years, after April 20 in 1 year out of 10. Fall: the first frost comes before October 26 in 1 year out of 10, before November 18 in half of the years, before December 10 in 9 years out of 10. Typical frost-free season: 239 days.JFMAMJJASONDLast frost ~Mar 27First 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.

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)April 20October 26
50% (typical)March 27November 18
90% (likely)February 26December 10
Frost-free season (32°F, 50% chance)
239 days
Hard frost (28°F), last in spring, 50% chance after
February 14
Hard frost (28°F), first in fall, 50% chance before
December 9

The last 15 years (2006–2020 normals)

Typical last frost March 25 (2 days earlier than the 30-year normal), typical first fall frost November 23 (5 days later). Frost-free season 245 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 Sandy: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 20, 20% April 10, 30% April 3, 40% March 30, 50% March 27, 60% March 21, 70% March 13, 80% March 5, 90% February 26. Observed last spring frost in recent years: 2021 April 12, 2022 April 14, 2023 April 20, 2024 March 14, 2025 March 14, 2026 April 15.Spring: last frostChance of a frost after this date10%50%90%Mar 1Apr 1May 1Apr 20Mar 27Feb 262021: April 122022: April 142023: April 202024: March 142025: March 142026: April 15Fall near Sandy: chance of a frost before this dateFall, chance of a frost before the date: 10% October 26, 20% November 3, 30% November 8, 40% November 13, 50% November 18, 60% November 24, 70% November 29, 80% December 3, 90% December 10. Observed first fall frost in recent years: 2021 December 14, 2022 November 7, 2023 October 27, 2024 November 19, 2025 December 1.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Oct 26Nov 18Dec 102021: December 142022: November 72023: October 272024: November 192025: December 1
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 12December 14
2022April 14November 7
2023April 20October 27
2024March 14November 19
2025March 14December 1
2026April 15season not over yet

What these dates mean

April 20 is the cautious light-frost date for the Sandy area; with only a 10 % chance of a frost later, it marks the point when a gardener can set out tender crops with low risk. The comparable cautious fall date is October 26, when there is only a 10 % chance that a frost has arrived earlier, making it the latest practical time to finish harvesting tender crops.

The 50 % dates indicate equal odds of a frost occurring. For light frost the median dates are March 27 in spring and November 18 in fall, while the hard-frost median dates are February 14 and December 9. A hard frost at 28 °F can damage plants that survive a light frost at 32 °F. These dates are drawn from 29 years of NOAA records, and the interval between the two 32 °F 50 % dates spans 239 days.

How to read the probabilities

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

  • Spring: "10% after April 20" 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 26" 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 Sandy, ORNumbered nearest stations: 1 — Estacada, OR — 15 mi; 2 — near Cascade Locks, OR — 16 mi; 3 — Government Camp, OR — 22 mi; 4 — Three Lynx, OR — 23 mi; 5 — Portland, OR — 24 mi.WA25 mi · 40 km1. Estacada, OR — 15 mi12. near Cascade Locks, OR — 16 mi23. Government Camp, OR — 22 mi34. Three Lynx, OR — 23 mi45. Portland, OR — 24 mi5
  1. Estacada, OR 15 mi (24 km)
  2. near Cascade Locks, OR 16 mi (26 km)
  3. Government Camp, OR 22 mi (36 km)
  4. Three Lynx, OR 23 mi (37 km)
  5. Portland, OR 24 mi (38 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: 45.4486, -122.1547.