Altadena, CA
How exposed is Altadena to wildfire?
Altadena's 20,358 buildings earn a 100th-percentile wildfire-risk score nationally under USFS's model — in USFS's highest wildfire-risk band nationally. (Source: USFS's Wildfire Risk to Communities methodology.)
USFS's separate burn-probability score — fire likelihood alone, before counting what's built there — puts Altadena at the 99th percentile, close to its 100th-percentile risk score.
Where Altadena's buildings actually sit
63.9% of Altadena's 20,358 buildings fall in USFS's Indirect exposure zone — ember cast rather than direct flame — against 17.8% Direct and 18.3% Minimal. Vent screens and roofing material matter more here than lot clearing alone. At 20,358 buildings, this is a substantial built environment, so the shares below describe a real population of structures, not a handful of edge cases.
How Altadena compares
Altadena scores 100th nationally and 95th within California — close enough that its state context doesn't change the picture the national number already gives. Among the 31,521 US communities USFS scores, Altadena ranks 115 for wildfire risk (1 is highest) and 692 by building count (1 is largest). Within California alone, it ranks 72 of 1,570 places by risk. See the full county-by-county picture for California on its state page.
Shopping for coverage in Altadena
Altadena's 100th-percentile score lands in California, the only two states requiring a wildfire disclosure at sale. California's surplus-lines homeowners market passed 300,000 policies for the first time in 2025, driven by carriers pulling back from wildfire-exposed areas statewide. The disclosure-law guide covers what it requires.
Hardening a home in Altadena
With ember exposure the dominant pattern in Altadena (63.9% Indirect), vent screens and roofing material tend to matter more than lot clearing alone. The home-hardening guide covers both.
More on how this number was built
The methodology guide shows exactly how USFS turned 20,358 counted buildings into the percentiles shown above for Altadena. For more on what indirect exposure implies beyond Altadena, see the exposure-zones guide.