Fencing · Hot & dry

How a wood fence ages in Los Angeles, CA

THE SHORT ANSWER

In Los Angeles, sun does most of the damage. UV here ranks #5 of 25 cities we cover, with about 26 days a year above 90 °F. Untreated pickets bleach to a pale silver and open up surface checks; with a decay index of only 8.5, rot is a slow, secondary risk. Model estimate: 16–21 years untreated, 21–27 years sealed on schedule.

Main threat
Sun & UV
Climate profile
Hot & dry
Expected life (untreated)
16–21 yrs
Fully gray by
Year 2
Best seal window
Jul – Aug
Sealed on schedule
21–27 yrs
Simulated wood fence in Los Angeles, CA after 10 years
Year 10Deep checks
MODEL SIMULATION
Los Angeles, CA · cedar pickets on wood posts, no stain
Color lossSevere
Surface checkingHigh
Mildew / rotMinimal
Fails first hereSun-side pickets: checks and cupping

Storyboard

20 years in Los Angeles, untreated

Wood fence in Los Angeles, install: Fresh boards
InstallFresh boards
Wood fence in Los Angeles, year 1: Sun-bleached silver
Year 1Sun-bleached silver
Wood fence in Los Angeles, year 3: Sun-bleached silver
Year 3Sun-bleached silver
Wood fence in Los Angeles, year 5: Surface checks
Year 5Surface checks
Wood fence in Los Angeles, year 10: Deep checks
Year 10Deep checks
Wood fence in Los Angeles, year 15: Rot at the base — posts may lean, deep checks
Year 15Rot at the base — posts may lean, deep checks
Wood fence in Los Angeles, year 20: Rot at the base — posts may lean, deep checks
Year 20Rot at the base — posts may lean, deep checks

Los Angeles’s wear fingerprint

Each bar is scaled to the highest of the 25 cities we cover; the black line marks the median.

Rainy days / yr34.1 · Low
Avg humidity57.4% · Low
Decay index8.5 · Low
UV index (avg)1.5 · High
Freeze–thaw days0 · Low
Days ≥ 90 °F25.5 · Typical

NOAA station LOS ANGELES DOWNTOWN/USC (USW00093134, 5.5 km away), 1991–2020 normals · humidity & UV: NASA POWER.

What fails first here

  1. 1Sun bleaching & raised grainSurface fibers break down under strong sun and wash away, leaving a pale, fuzzy texture.
  2. 2Checks, splits and cuppingStrong UV (rank #5 of 25) dries and shrinks the surface faster than the core, opening fine cracks.
  3. 3GrayingCosmetic, and fast: our model has the surface fully silver by year 2. Not damage on its own, but it means the protective surface is gone.
  4. 4Rot at post basesSlow here (decay index 8.5), but posts set in soil still fail first.

Upkeep

Los Angeles maintenance calendar

Built from local normals: bar width is the share of days with rain; sealant needs 2–3 dry days between 50 and 88 °F.

Jan
Feb
MarInspect ends & fasteners
Apr
May
Jun
JulStain / seal
AugStain / seal
Sep
Oct
Nov
Dec

Pin-ready

Save it for when you build.

The 20-year storyboard as a tall pin, linking back to this page.

Pinterest storyboard: wood fence in Los Angeles, CA, new to year 20

Wood fences in similar climates

…and in very different ones

Questions Los Angeles owners ask

How long does a wood fence last in Los Angeles?

Our model puts it at 16–21 years untreated and 21–27 years if it is sealed every 2–3 years. The national typical range is 15–20 yrs; Los Angeles’s sun & uv profile is why the local number differs.

When is the best time to seal a wood fence in Los Angeles?

July and August: the months with the fewest rainy days while average temperatures sit between 50 and 88 °F. Most sealants need 2–3 dry days to cure.

How long do fence posts last in Los Angeles?

Posts are usually the first part of a wood fence to go, because they sit in damp soil. With a decay index of 8.5 here, plan on inspecting post bases from about year 10.

Why does wood turn white or pale in Los Angeles?

UV breaks down lignin at the surface; rain and wind wash the loose fibers away, leaving a bleached, silvery layer. It is cosmetic until checks open up.

Model simulation, not a guarantee: south-facing, full sun, no shade or ground-contact surprises. How it works.