Decking · Hot & dry
How long does a pressure-treated deck last in San Diego, CA?
In San Diego, sun does most of the damage. UV here ranks #9 of 25 cities we cover. Unsealed boards bleach to a pale silver and open up surface checks; with a decay index of only 12, rot is a slow, secondary risk. Model estimate: 12–15 years unsealed, 16–21 years sealed on schedule.
Storyboard
20 years in San Diego, unsealed
San Diego’s wear fingerprint
Each bar is scaled to the highest of the 25 cities we cover; the black line marks the median.
NOAA station SAN DIEGO INTL AP (USW00023188, 2.6 km away), 1991–2020 normals · humidity & UV: NASA POWER.
What fails first here
- 1Checks, splits and warpingStrong UV (rank #9 of 25) dries and shrinks the surface faster than the core, opening fine cracks.
- 2Sun bleaching & raised grainSurface fibers break down under strong sun and wash away, leaving a pale, fuzzy texture.
- 3Rot at board ends & joistsSlow here (decay index 12), but ends and joists under planters still fail first.
- 4GrayingCosmetic, 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.
Upkeep
San Diego 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.
Same city, other materials
How the alternatives age in San Diego
Pin-ready
Save it for when you build.
The 20-year storyboard as a tall pin, linking back to this page.
Pressure-treated decks in similar climates
Los Angeles, CA
San Francisco, CA
Charleston, SC
Portland, OR
New York, NY…and in very different ones
New Orleans, LA
Miami, FL
Tampa, FLQuestions San Diego owners ask
How long does a pressure-treated deck last in San Diego?
Our model puts it at 12–15 years unsealed and 16–21 years if it is sealed every 2–3 years. The national typical range is 10–15 yrs; San Diego’s sun and UV profile is why the local number differs.
When is the best time to seal a pressure-treated deck in San Diego?
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.
Cedar or pressure-treated: which lasts longer in San Diego?
Our model gives an unsealed pressure-treated deck 12–15 years here and untreated cedar 18–24 years. Where rot is slow, cedar’s stability wins: treated pine checks and warps faster in sun and frost.
Why does wood turn white or pale in San Diego?
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.