Diamond Bar, CA
Diamond Bar wildfire risk explained
Diamond Bar's 16,161 buildings earn a 90th-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 Diamond Bar at the 90th percentile, close to its 90th-percentile risk score.
Diamond Bar's building exposure, zone by zone
16,161 buildings are counted in Diamond Bar, and 56.7% of them are Indirect exposure — ember-driven risk rather than the 7.5% in Direct exposure or the 35.9% rated Minimal. At 16,161 buildings, this is a substantial built environment, so the shares below describe a real population of structures, not a handful of edge cases.
Diamond Bar against the rest of the country
Inside California, Diamond Bar sits at just the 61st percentile even though it scores 90th nationally — the state's overall wildfire exposure is high enough to make this a relatively quiet corner of it. Among the 31,521 US communities USFS scores, Diamond Bar ranks 3,268 for wildfire risk (1 is highest) and 902 by building count (1 is largest). Within California alone, it ranks 618 of 1,570 places by risk. See the full county-by-county picture for California on its state page.
What this risk score means for insurance
Because Diamond Bar is in California, a wildfire-hazard disclosure is legally required before a sale closes here — unusual nationally, since only these two states mandate it. The state's FAIR Plan alone carried 668,609 policies by the end of 2025. Full detail in the disclosure-law guide.
What would actually reduce this score
With ember exposure the dominant pattern in Diamond Bar (56.7% 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
Diamond Bar's 90th-percentile score and its burn-probability figure both come from the same USFS workbook, documented in the methodology guide. For more on what indirect exposure implies beyond Diamond Bar, see the exposure-zones guide.