U.S. Frost Dates by Weather Station

NOAA station USC00041424 · California

Frost Dates for Campo, CA

NOAA weather station Campo (USC00041424), California · elevation 2630 ft (802 m) · hardiness zone 9a*

  • Lower-risk planting dateafter June 1only 1 spring in 10 still has a frost later
  • Typical last frostApril 3050% chance of a frost after it
  • Typical first fall frostOctober 2650% chance of a frost before it
  • Frost-free season174 daystypical year, 32°F
  • Hardiness zone9acalculated*

The year at a glance

Frost season at Campo, CASpring: a frost after April 9 in 9 years out of 10, after April 30 in half of the years, after June 1 in 1 year out of 10. Fall: the first frost comes before September 30 in 1 year out of 10, before October 26 in half of the years, before November 12 in 9 years out of 10. Typical frost-free season: 174 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 30First frost ~Oct 26Frost season at Campo, CASpring: a frost after April 9 in 9 years out of 10, after April 30 in half of the years, after June 1 in 1 year out of 10. Fall: the first frost comes before September 30 in 1 year out of 10, before October 26 in half of the years, before November 12 in 9 years out of 10. Typical frost-free season: 174 days.JFMAMJJASONDLast frost ~Apr 30First frost ~Oct 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.

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)June 1September 30
50% (typical)April 30October 26
90% (likely)April 9November 12
Frost-free season (32°F, 50% chance)
174 days
Hard frost (28°F), last in spring, 50% chance after
April 2
Hard frost (28°F), first in fall, 50% chance before
November 14

The last 15 years (2006–2020 normals)

Typical last frost May 12 (12 days later than the 30-year normal), typical first fall frost October 25 (1 day earlier). Frost-free season 165 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 Campo: chance of a frost after this dateSpring, chance of a frost after the date: 10% June 1, 20% May 19, 30% May 13, 40% May 4, 50% April 30, 60% April 25, 70% April 20, 80% April 16, 90% April 9. Observed last spring frost in recent years: 2021 May 27, 2022 June 19, 2023 May 8, 2024 May 6, 2025 May 25, 2026 May 6.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1Jun 1Jun 1Apr 30Apr 92021: May 272022: June 192023: May 82024: May 62025: May 252026: May 6Fall at Campo: chance of a frost before this dateFall, chance of a frost before the date: 10% September 30, 20% October 9, 30% October 15, 40% October 21, 50% October 26, 60% October 30, 70% November 2, 80% November 6, 90% November 12. Observed first fall frost in recent years: 2021 October 11, 2022 October 14, 2023 October 28, 2024 October 30, 2025 November 25.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Dec 1Sep 30Oct 26Nov 122021: October 112022: October 142023: October 282024: October 302025: November 25
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
2021May 27October 11
2022June 19October 14
2023May 8October 28
2024May 6October 30
2025May 25November 25
2026May 6season not over yet

What these dates mean

Setting tender crops on April 9 carries a 90 % chance of a light frost, making it a gamble for Campo gardeners.

The 50% spring date is April 30, meaning there is a 50 % chance of a frost later than this date. A cautious plan uses June 1, which has only a 10 % chance of a frost later, to start tender crops. In the autumn, the 50% date is October 26, with a 50 % chance of a frost earlier than that date, while September 30 is the cautious date, offering just a 10 % chance of an earlier frost for finishing tender crops.

A hard frost at 28 °F, represented by the median dates April 2 in spring and November 14 in fall, can damage plant tissue that would survive a light frost at 32 °F.

How to read the probabilities

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

  • Spring: "10% after June 1" 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 September 30" 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 Campo, CANumbered nearest stations: 1 — near Aguanga, CA — 56 mi; 2 — Big Bear Lake, CA — 115 mi; 3 — near Barstow, CA — 155 mi; 4 — Sandberg, CA — 195 mi; 5 — Bagdad, AZ — 233 mi.AZ100 mi · 161 km1. near Aguanga, CA — 56 mi12. Big Bear Lake, CA — 115 mi23. near Barstow, CA — 155 mi34. Sandberg, CA — 195 mi45. Bagdad, AZ — 233 mi5
  1. near Aguanga, CA 56 mi (90 km)
  2. Big Bear Lake, CA 115 mi (184 km)
  3. near Barstow, CA 155 mi (249 km)
  4. Sandberg, CA 195 mi (315 km)
  5. Bagdad, AZ 233 mi (376 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: 32.6264, -116.47.