U.S. Frost Dates by Weather Station

NOAA station USW00024225 · Oregon

Frost Dates near Medford, OR

NOAA weather station Medford Rogue Valley Airport (USW00024225), Oregon · elevation 1297 ft (395 m) · hardiness zone 8b*

Medford is the nearest town to the station (3.8 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 30only 1 spring in 10 still has a frost later
  • Typical last frostApril 850% chance of a frost after it
  • Typical first fall frostOctober 2950% chance of a frost before it
  • Frost-free season204 daystypical year, 32°F
  • Hardiness zone8bcalculated*

The year at a glance

Frost season near Medford, ORSpring: a frost after March 17 in 9 years out of 10, after April 8 in half of the years, after April 30 in 1 year out of 10. Fall: the first frost comes before October 14 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: 204 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 8First frost ~Oct 29Frost season near Medford, ORSpring: a frost after March 17 in 9 years out of 10, after April 8 in half of the years, after April 30 in 1 year out of 10. Fall: the first frost comes before October 14 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: 204 days.JFMAMJJASONDLast frost ~Apr 8First 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 26 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)April 30October 14
50% (typical)April 8October 29
90% (likely)March 17November 16
Frost-free season (32°F, 50% chance)
204 days
Hard frost (28°F), last in spring, 50% chance after
March 10
Hard frost (28°F), first in fall, 50% chance before
November 13

The last 15 years (2006–2020 normals)

Typical last frost April 5 (3 days earlier than the 30-year normal), typical first fall frost November 1 (3 days later). Frost-free season 208 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 Medford: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 30, 20% April 23, 30% April 18, 40% April 12, 50% April 8, 60% April 3, 70% March 30, 80% March 25, 90% March 17. Observed last spring frost in recent years: 2021 April 11, 2022 April 15, 2023 April 13, 2024 March 14, 2025 March 8, 2026 April 17.Spring: last frostChance of a frost after this date10%50%90%Mar 1Apr 1May 1Apr 30Apr 8Mar 172021: April 112022: April 152023: April 132024: March 142025: March 82026: April 17Fall near Medford: chance of a frost before this dateFall, chance of a frost before the date: 10% October 14, 20% October 19, 30% October 23, 40% October 26, 50% October 29, 60% October 31, 70% November 4, 80% November 8, 90% November 16. Observed first fall frost in recent years: 2021 October 12, 2022 November 10, 2023 October 28, 2024 October 24, 2025 November 21.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 14Oct 29Nov 162021: October 122022: November 102023: October 282024: October 242025: November 21
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 15November 10
2023April 13October 28
2024March 14October 24
2025March 8November 21
2026April 17season not over yet

What these dates mean

204 days between the 50% dates of April 8 and October 29 frame the period in the Medford area when a light frost (32 °F) is less likely than not. The 50% light-frost dates are a reference point, not a frost event; similarly the 50% hard-frost dates are March 10 and November 13, indicating even odds for a 28 °F hard frost.

For tender crops, the cautious spring date is April 30, when there is only a 10 % chance of a later frost, while planting on March 17 carries a 90 % chance and is a gamble. In fall, October 14 serves as the cautious date to finish harvesting tender crops, with only a 10 % chance of an earlier frost; waiting until November 16 involves a 90 % chance and is a gamble. A hard frost matters more than a light frost because the lower temperature can damage plant tissue that survives a 32 °F event.

How to read the probabilities

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

  • Spring: "10% after April 30" 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 14" 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 Medford, ORNumbered nearest stations: 1 — near Shady Cove, OR — 22 mi; 2 — Sexton Summit, OR — 29 mi; 3 — Prospect, OR — 30 mi; 4 — Riddle, OR — 46 mi; 5 — near Roseburg, OR — 63 mi.CA25 mi · 40 km1. near Shady Cove, OR — 22 mi12. Sexton Summit, OR — 29 mi23. Prospect, OR — 30 mi34. Riddle, OR — 46 mi45. near Roseburg, OR — 63 mi5
  1. near Shady Cove, OR 22 mi (36 km)
  2. Sexton Summit, OR 29 mi (47 km)
  3. Prospect, OR 30 mi (49 km)
  4. Riddle, OR 46 mi (75 km)
  5. near Roseburg, OR 63 mi (101 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: 42.3811, -122.8722.