U.S. Frost Dates by Weather Station

NOAA station USW00023187 · California

Frost Dates for Sandberg, CA

NOAA weather station Sandberg (USW00023187), California · elevation 4510 ft (1375 m) · hardiness zone 9a*

  • Lower-risk planting dateafter May 9only 1 spring in 10 still has a frost later
  • Typical last frostApril 1550% chance of a frost after it
  • Typical first fall frostNovember 2650% chance of a frost before it
  • Frost-free season224 daystypical year, 32°F
  • Hardiness zone9acalculated*

The year at a glance

Frost season at Sandberg, CASpring: a frost after March 9 in 9 years out of 10, after April 15 in half of the years, after May 9 in 1 year out of 10. Fall: the first frost comes before November 1 in 1 year out of 10, before November 26 in half of the years, before December 16 in 9 years out of 10. Typical frost-free season: 224 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 15First frost ~Nov 26Frost season at Sandberg, CASpring: a frost after March 9 in 9 years out of 10, after April 15 in half of the years, after May 9 in 1 year out of 10. Fall: the first frost comes before November 1 in 1 year out of 10, before November 26 in half of the years, before December 16 in 9 years out of 10. Typical frost-free season: 224 days.JFMAMJJASONDLast frost ~Apr 15First frost ~Nov 26
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 27 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 9November 1
50% (typical)April 15November 26
90% (likely)March 9December 16
Frost-free season (32°F, 50% chance)
224 days
Hard frost (28°F), last in spring, 50% chance after
March 11
Hard frost (28°F), first in fall, 50% chance before
December 12

The last 15 years (2006–2020 normals)

Typical last frost April 16 (1 day later than the 30-year normal), typical first fall frost November 26. Frost-free season 220 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 Sandberg: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 9, 20% May 1, 30% April 26, 40% April 20, 50% April 15, 60% April 9, 70% April 5, 80% March 25, 90% March 9. Observed last spring frost in recent years: 2021 March 16, 2022 May 11, 2023 May 4, 2024 April 14, 2025 April 27, 2026 February 21.Spring: last frostChance of a frost after this date10%50%90%Mar 1Apr 1May 1May 9Apr 15Mar 92021: March 162022: May 112023: May 42024: April 142025: April 272026: February 21Fall at Sandberg: chance of a frost before this dateFall, chance of a frost before the date: 10% November 1, 20% November 8, 30% November 15, 40% November 20, 50% November 26, 60% December 1, 70% December 4, 80% December 9, 90% December 16. Observed first fall frost in recent years: 2021 December 14, 2022 November 3, 2023 January 7, 2024 January 13, 2025 November 21.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Jan 1Nov 1Nov 26Dec 162021: December 142022: November 32023: January 72024: January 132025: 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
2021March 16December 14
2022May 11November 3
2023May 4January 7
2024April 14January 13
2025April 27November 21
2026February 21season not over yet

What these dates mean

May 9 is the cautious spring light-frost date, with only a 10 % chance of a frost later than that day, and it lets a gardener schedule the first planting of tender crops with minimal risk. The 50% date is April 15, indicating a 50 % chance of a light frost later than this date, while the 50% date is November 26, indicating a 50 % chance of a light frost earlier than this date. In the fall the cautious date is November 1, when there is only a 10 % chance that a frost has arrived earlier, providing a reliable endpoint for harvesting tender crops. Hard-frost thresholds at 28 °F, marked by the median dates March 11 and December 12, matter more because temperatures that low can injure plant tissue that usually survives a 32 °F 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 May 9" 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 November 1" 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 Sandberg, CANumbered nearest stations: 1 — near Corcoran, CA — 105 mi; 2 — Big Bear Lake, CA — 109 mi; 3 — near Barstow, CA — 110 mi; 4 — Paso Robles (Airport), CA — 125 mi; 5 — Paso Robles, CA — 126 mi.CA50 mi · 80 km1. near Corcoran, CA — 105 mi12. Big Bear Lake, CA — 109 mi23. near Barstow, CA — 110 mi34. Paso Robles (Airport), CA — 125 mi45. Paso Robles, CA — 126 mi5
  1. near Corcoran, CA 105 mi (169 km)
  2. Big Bear Lake, CA 109 mi (175 km)
  3. near Barstow, CA 110 mi (177 km)
  4. Paso Robles (Airport), CA 125 mi (201 km)
  5. Paso Robles, CA 126 mi (204 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: 34.7436, -118.7242.