U.S. Frost Dates by Weather Station

NOAA station USW00093209 · California

Frost Dates for Paso Robles (Airport), CA

NOAA weather station Paso Robles Municipal Airport (USW00093209), California · elevation 810 ft (247 m) · hardiness zone 9a*

  • Lower-risk planting dateafter April 27only 1 spring in 10 still has a frost later
  • Typical last frostApril 450% chance of a frost after it
  • Typical first fall frostNovember 550% chance of a frost before it
  • Frost-free season213 daystypical year, 32°F
  • Hardiness zone9acalculated*

The year at a glance

Frost season at Paso Robles (Airport), CASpring: a frost after March 2 in 9 years out of 10, after April 4 in half of the years, after April 27 in 1 year out of 10. Fall: the first frost comes before October 17 in 1 year out of 10, before November 5 in half of the years, before November 24 in 9 years out of 10. Typical frost-free season: 213 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 4First frost ~Nov 5Frost season at Paso Robles (Airport), CASpring: a frost after March 2 in 9 years out of 10, after April 4 in half of the years, after April 27 in 1 year out of 10. Fall: the first frost comes before October 17 in 1 year out of 10, before November 5 in half of the years, before November 24 in 9 years out of 10. Typical frost-free season: 213 days.JFMAMJJASONDLast frost ~Apr 4First frost ~Nov 5
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 27 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)April 27October 17
50% (typical)April 4November 5
90% (likely)March 2November 24
Frost-free season (32°F, 50% chance)
213 days
Hard frost (28°F), last in spring, 50% chance after
February 22
Hard frost (28°F), first in fall, 50% chance before
November 21

The last 15 years (2006–2020 normals)

Typical last frost March 31 (4 days earlier than the 30-year normal), typical first fall frost November 5. Frost-free season 218 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 Paso Robles (Airport): chance of a frost after this dateSpring, chance of a frost after the date: 10% April 27, 20% April 21, 30% April 14, 40% April 9, 50% April 4, 60% March 31, 70% March 25, 80% March 15, 90% March 2. Observed last spring frost in recent years: 2021 March 24, 2022 April 13, 2023 April 5, 2024 April 6, 2025 March 19, 2026 February 22.Spring: last frostChance of a frost after this date10%50%90%Mar 1Apr 1May 1Apr 27Apr 4Mar 22021: March 242022: April 132023: April 52024: April 62025: March 192026: February 22Fall at Paso Robles (Airport): chance of a frost before this dateFall, chance of a frost before the date: 10% October 17, 20% October 23, 30% October 29, 40% November 1, 50% November 5, 60% November 9, 70% November 13, 80% November 18, 90% November 24. Observed first fall frost in recent years: 2021 November 24, 2022 November 3, 2023 October 29, 2024 October 31, 2025 November 26.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Oct 17Nov 5Nov 242021: November 242022: November 32023: October 292024: October 312025: November 26
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 24November 24
2022April 13November 3
2023April 5October 29
2024April 6October 31
2025March 19November 26
2026February 22season not over yet

What these dates mean

April 27 is the cautious spring date for Paso Robles (Airport); with only a 10 % chance of a light frost after that day, a gardener can plan to set out tender crops.

April 4 marks the 50 % light-frost date in spring, meaning there is a 50 % chance of a light frost later than this date, while November 5 is the 50 % light-frost date in fall, with a 50 % chance of a light frost earlier than this date. The cautious fall date is October 17, when a light frost has only a 10 % chance of having arrived, allowing the gardener to finish harvesting tender crops. February 22 and November 21 are the 50 % hard-frost dates, indicating equal odds of a hard frost (28 °F) occurring.

A hard frost matters more than a light frost because temperatures of 28 °F can damage plants that would survive the milder 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 April 27" 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 17" 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 Paso Robles (Airport), CANumbered nearest stations: 1 — Paso Robles, CA — 4 mi; 2 — King City, CA — 47 mi; 3 — near Corcoran, CA — 66 mi; 4 — Auberry, CA — 116 mi; 5 — Lodgepole, CA — 124 mi.CA25 mi · 40 km1. Paso Robles, CA — 4 mi12. King City, CA — 47 mi23. near Corcoran, CA — 66 mi34. Auberry, CA — 116 mi45. Lodgepole, CA — 124 mi5
  1. Paso Robles, CA 4 mi (7 km)
  2. King City, CA 47 mi (75 km)
  3. near Corcoran, CA 66 mi (106 km)
  4. Auberry, CA 116 mi (187 km)
  5. Lodgepole, CA 124 mi (199 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: 35.6697, -120.6283.