U.S. Frost Dates by Weather Station

NOAA station USC00048606 · California

Frost Dates for Strawberry Valley, CA

NOAA weather station Strawberry Valley (USC00048606), California · elevation 3808 ft (1161 m) · hardiness zone 8b*

  • Lower-risk planting dateafter May 31only 1 spring in 10 still has a frost later
  • Typical last frostMay 450% chance of a frost after it
  • Typical first fall frostOctober 3050% chance of a frost before it
  • Frost-free season174 daystypical year, 32°F
  • Hardiness zone8bcalculated*

The year at a glance

Frost season at Strawberry Valley, CASpring: a frost after April 18 in 9 years out of 10, after May 4 in half of the years, after May 31 in 1 year out of 10. Fall: the first frost comes before October 7 in 1 year out of 10, before October 30 in half of the years, before November 14 in 9 years out of 10. Typical frost-free season: 174 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 4First frost ~Oct 30Frost season at Strawberry Valley, CASpring: a frost after April 18 in 9 years out of 10, after May 4 in half of the years, after May 31 in 1 year out of 10. Fall: the first frost comes before October 7 in 1 year out of 10, before October 30 in half of the years, before November 14 in 9 years out of 10. Typical frost-free season: 174 days.JFMAMJJASONDLast frost ~May 4First frost ~Oct 30
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 30 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 31October 7
50% (typical)May 4October 30
90% (likely)April 18November 14
Frost-free season (32°F, 50% chance)
174 days
Hard frost (28°F), last in spring, 50% chance after
April 15
Hard frost (28°F), first in fall, 50% chance before
November 16

The last 15 years (2006–2020 normals)

Typical last frost May 2 (2 days earlier than the 30-year normal), typical first fall frost October 26 (4 days earlier). Frost-free season 175 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 Strawberry Valley: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 31, 20% May 23, 30% May 14, 40% May 9, 50% May 4, 60% April 30, 70% April 27, 80% April 22, 90% April 18. Observed last spring frost in recent years: 2021 June 10, 2026 April 13.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 31May 4Apr 182021: June 102026: April 13Fall at Strawberry Valley: chance of a frost before this dateFall, chance of a frost before the date: 10% October 7, 20% October 15, 30% October 19, 40% October 24, 50% October 30, 60% November 1, 70% November 5, 80% November 8, 90% November 14. Observed first fall frost in recent years: 2021 October 10, 2022 November 3, 2025 November 15.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 7Oct 30Nov 142021: October 102022: November 32025: November 15
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
2021June 10October 10
2022incomplete recordNovember 3
2023incomplete recordincomplete record
2024incomplete recordincomplete record
2025incomplete recordNovember 15
2026April 13season not over yet

What these dates mean

October 7 marks the cautious fall date in Strawberry Valley for finishing the harvest of tender crops, with only a 10 % chance that a light frost has arrived earlier.

In spring, the cautious date for setting out tender crops is May 31, when the probability of a light frost later than that date is just 10 %. The 50 % light-frost date is May 4, which represents a 50 % chance of a frost later than this date. The median light-frost date in fall is October 30, indicating a 50 % chance of a frost earlier than this date, while October 7 remains the cautious point with only a 10 % chance of an earlier frost.

Hard frost at 28 °F, reflected by the median dates April 15 and November 16, can injure plant tissue that survives a light 32 °F freeze, making it the more critical threshold.

How to read the probabilities

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

  • Spring: "10% after May 31" 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 7" 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 Strawberry Valley, CANumbered nearest stations: 1 — Nevada City, CA — 23 mi; 2 — near Grass Valley, CA — 25 mi; 3 — Portola, CA — 38 mi; 4 — near Greenville, CA — 42 mi; 5 — Chester, CA — 52 mi.CANV25 mi · 40 km1. Nevada City, CA — 23 mi12. near Grass Valley, CA — 25 mi23. Portola, CA — 38 mi34. near Greenville, CA — 42 mi45. Chester, CA — 52 mi5
  1. Nevada City, CA 23 mi (36 km)
  2. near Grass Valley, CA 25 mi (40 km)
  3. Portola, CA 38 mi (61 km)
  4. near Greenville, CA 42 mi (68 km)
  5. Chester, CA 52 mi (83 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: 39.5631, -121.1078.