Castro Valley, CA
Castro Valley wildfire risk explained
Castro Valley's 22,432 buildings earn a 94th-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 Castro Valley at the 95th percentile, close to its 94th-percentile risk score.
What "at risk" means for the buildings here
Most of Castro Valley's buildings (60.3%) sit in the Indirect zone, where wind-blown embers rather than flame front are the mechanism USFS is scoring — ember-resistant vents and non-combustible roofing are the interventions this pattern favors, more than defensible space alone. At 22,432 buildings, this is a substantial built environment, so the shares below describe a real population of structures, not a handful of edge cases.
Where Castro Valley ranks
Castro Valley's 94th national percentile looks worse in isolation than its 72nd ranking inside California does — this place is on the milder end for its own state, by 22 points. Among the 31,521 US communities USFS scores, Castro Valley ranks 1,817 for wildfire risk (1 is highest) and 599 by building count (1 is largest). Within California alone, it ranks 443 of 1,570 places by risk. See the full county-by-county picture for California on its state page.
Castro Valley and the insurance market
Castro Valley's 94th-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 Castro Valley
Castro Valley's 60.3% Indirect-exposure share points at embers, not flame contact, as the main pathway — ember-resistant vents and non-combustible roofing rank ahead of defensible space here. Detail in the home-hardening guide.
Where Castro Valley's figures come from
Every one of the two percentiles behind Castro Valley's 1,817-place national rank traces to USFS's Wildfire Risk to Communities dataset — see the methodology guide. The exposure-zones guide covers what Castro Valley's dominant indirect exposure actually means, with real examples from across the dataset.