U.S. Frost Dates by Weather Station

NOAA station USW00023161 · California

Frost Dates near Barstow, CA

NOAA weather station Barstow Daggett Airport (USW00023161), California · elevation 1917 ft (584 m) · hardiness zone 9a*

Barstow is the nearest town to the station (13.8 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 March 11only 1 spring in 10 still has a frost later
  • Typical last frostFebruary 1950% chance of a frost after it
  • Typical first fall frostNovember 2650% chance of a frost before it
  • Frost-free season279 daystypical year, 32°F
  • Hardiness zone9acalculated*

The year at a glance

Frost season near Barstow, CASpring: a frost after January 23 in 9 years out of 10, after February 19 in half of the years, after March 11 in 1 year out of 10. Fall: the first frost comes before November 10 in 1 year out of 10, before November 26 in half of the years, before December 11 in 9 years out of 10. Typical frost-free season: 279 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Feb 19First frost ~Nov 26Frost season near Barstow, CASpring: a frost after January 23 in 9 years out of 10, after February 19 in half of the years, after March 11 in 1 year out of 10. Fall: the first frost comes before November 10 in 1 year out of 10, before November 26 in half of the years, before December 11 in 9 years out of 10. Typical frost-free season: 279 days.JFMAMJJASONDLast frost ~Feb 19First 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.

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)March 11November 10
50% (typical)February 19November 26
90% (likely)January 23December 11
Frost-free season (32°F, 50% chance)
279 days
Hard frost (28°F), last in spring, 50% chance after
January 28
Hard frost (28°F), first in fall, 50% chance before
December 9

The last 15 years (2006–2020 normals)

Typical last frost February 23 (4 days later than the 30-year normal), typical first fall frost November 26. Frost-free season 276 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 Barstow: chance of a frost after this dateSpring, chance of a frost after the date: 10% March 11, 20% March 4, 30% February 28, 40% February 24, 50% February 19, 60% February 13, 70% February 7, 80% February 1, 90% January 23. Observed last spring frost in recent years: 2021 March 1, 2022 February 27, 2023 February 27, 2024 February 12, 2025 January 25, 2026 February 21.Spring: last frostChance of a frost after this date10%50%90%Feb 1Mar 1Mar 11Feb 19Jan 232021: March 12022: February 272023: February 272024: February 122025: January 252026: February 21Fall near Barstow: chance of a frost before this dateFall, chance of a frost before the date: 10% November 10, 20% November 16, 30% November 20, 40% November 23, 50% November 26, 60% November 30, 70% December 3, 80% December 6, 90% December 11. Observed first fall frost in recent years: 2021 December 10, 2022 November 21, 2023 November 25, 2024 November 20, 2025 December 29.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Jan 1Nov 10Nov 26Dec 112021: December 102022: November 212023: November 252024: November 202025: December 29
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 1December 10
2022February 27November 21
2023February 27November 25
2024February 12November 20
2025January 25December 29
2026February 21season not over yet

What these dates mean

The cautious fall date for finishing tender crops in the Barstow area is November 10, when there is only a 10 % chance a light frost has arrived; gardeners therefore aim to complete harvesting by that day to keep the risk low.

In spring the cautious date for setting out tender crops is March 11, which carries a 10 % chance of a light frost later in the season; planting earlier, such as on January 23, involves a 90 % chance of frost and is a gamble. The 50 % light-frost dates are February 19 in spring and November 26 in fall; the 50 % hard-frost dates are January 28 and December 9.

A hard frost at 28 °F can damage plant tissue more severely than a light frost at 32 °F, so the hard-frost dates are especially important for risk assessment.

How to read the probabilities

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

  • Spring: "10% after March 11" 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 10" 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 Barstow, CANumbered nearest stations: 1 — Big Bear Lake, CA — 43 mi; 2 — near Aguanga, CA — 102 mi; 3 — Pahrump, NV — 106 mi; 4 — Sandberg, CA — 110 mi; 5 — Mercury Desert Rock Airport, NV — 129 mi.CANVAZ100 mi · 161 km1. Big Bear Lake, CA — 43 mi12. near Aguanga, CA — 102 mi23. Pahrump, NV — 106 mi34. Sandberg, CA — 110 mi45. Mercury Desert Rock Airport, NV — 129 mi5
  1. Big Bear Lake, CA 43 mi (69 km)
  2. near Aguanga, CA 102 mi (164 km)
  3. Pahrump, NV 106 mi (170 km)
  4. Sandberg, CA 110 mi (177 km)
  5. Mercury Desert Rock Airport, NV 129 mi (208 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: 34.8536, -116.7858.