U.S. Frost Dates by Weather Station

NOAA station USC00355593 · Oregon

Frost Dates for Milton Freewater, OR

NOAA weather station Milton Freewater (USC00355593), Oregon · elevation 970 ft (296 m) · hardiness zone 7b*

  • Lower-risk planting dateafter April 16only 1 spring in 10 still has a frost later
  • Typical last frostMarch 2550% chance of a frost after it
  • Typical first fall frostOctober 2950% chance of a frost before it
  • Frost-free season218 daystypical year, 32°F
  • Hardiness zone7bcalculated*

The year at a glance

Frost season at Milton Freewater, ORSpring: a frost after March 6 in 9 years out of 10, after March 25 in half of the years, after April 16 in 1 year out of 10. Fall: the first frost comes before October 12 in 1 year out of 10, before October 29 in half of the years, before November 16 in 9 years out of 10. Typical frost-free season: 218 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Mar 25First frost ~Oct 29Frost season at Milton Freewater, ORSpring: a frost after March 6 in 9 years out of 10, after March 25 in half of the years, after April 16 in 1 year out of 10. Fall: the first frost comes before October 12 in 1 year out of 10, before October 29 in half of the years, before November 16 in 9 years out of 10. Typical frost-free season: 218 days.JFMAMJJASONDLast frost ~Mar 25First frost ~Oct 29
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 16October 12
50% (typical)March 25October 29
90% (likely)March 6November 16
Frost-free season (32°F, 50% chance)
218 days
Hard frost (28°F), last in spring, 50% chance after
March 5
Hard frost (28°F), first in fall, 50% chance before
November 11

The last 15 years (2006–2020 normals)

Typical last frost March 27 (2 days later than the 30-year normal), typical first fall frost October 31 (2 days later). Frost-free season 216 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 at Milton Freewater: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 16, 20% April 8, 30% April 3, 40% March 30, 50% March 25, 60% March 21, 70% March 16, 80% March 11, 90% March 6. Observed last spring frost in recent years: 2021 April 11, 2022 April 16, 2023 April 5, 2025 March 5.Spring: last frostChance of a frost after this date10%50%90%Mar 1Apr 1Apr 16Mar 25Mar 62021: April 112022: April 162023: April 52025: March 5Fall at Milton Freewater: chance of a frost before this dateFall, chance of a frost before the date: 10% October 12, 20% October 18, 30% October 22, 40% October 26, 50% October 29, 60% November 1, 70% November 5, 80% November 10, 90% November 16. Observed first fall frost in recent years: 2021 October 31, 2022 November 8, 2023 October 27, 2024 October 25, 2025 October 30.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 12Oct 29Nov 162021: October 312022: November 82023: October 272024: October 252025: October 30
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 31
2022April 16November 8
2023April 5October 27
2024incomplete recordOctober 25
2025March 5October 30
2026incomplete recordseason not over yet

What these dates mean

April 16 is the cautious spring date; with only a 10 % chance of a light frost later, it lets a gardener plan to set out tender crops.

The 50% date is March 25, a 50 % chance of a frost later than this date, and the 50% date is October 29, a 50 % chance of a frost earlier than this date. The 50% hard-frost dates are March 5 in spring and November 11 in fall. Hard frosts at 28 °F can cause more severe damage than light frosts at 32 °F. The record spans 29 years and the interval between the two 32°F 50% dates is 218 days.

October 12 is the cautious fall date, carrying only a 10 % chance of a light frost earlier, so it provides a guideline for finishing the harvest of tender crops.

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 12" 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 Milton Freewater, ORNumbered nearest stations: 1 — Whitman Mission, WA — 7 mi; 2 — Walla Walla, WA — 12 mi; 3 — Pendleton, OR — 28 mi; 4 — near Burbank, WA — 31 mi; 5 — Dayton, WA — 32 mi.ORID25 mi · 40 km1. Whitman Mission, WA — 7 mi12. Walla Walla, WA — 12 mi23. Pendleton, OR — 28 mi34. near Burbank, WA — 31 mi45. Dayton, WA — 32 mi5
  1. Whitman Mission, WA 7 mi (12 km)
  2. Walla Walla, WA 12 mi (19 km)
  3. Pendleton, OR 28 mi (44 km)
  4. near Burbank, WA 31 mi (49 km)
  5. Dayton, WA 32 mi (52 km)

Sources

* Hardiness zone 7b: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 45.9428, -118.4089.