Rio Oso, CA
Rio Oso wildfire risk explained
Rio Oso's 319 buildings earn a 81st-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.)
Separately from the risk score above, Rio Oso's burn probability — fire likelihood with no building count factored in — sits at the 81st percentile nationally.
Where Rio Oso's buildings actually sit
Of Rio Oso's 319 counted buildings, 97.8% carry Direct exposure and only 2.2% carry Minimal — a lopsided split that puts defensible-space clearing ahead of vents or roofing as the intervention worth doing first.
Where Rio Oso ranks
Inside California, Rio Oso sits at just the 41st percentile even though it scores 81st 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, Rio Oso ranks 6,107 for wildfire risk (1 is highest) and 21,112 by building count (1 is largest). Within California alone, it ranks 921 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
Rio Oso's 81st-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.
What would actually reduce this score
Rio Oso's 97.8% Direct-exposure share means lot clearing around the structure typically outweighs any single material upgrade here. The home-hardening guide ranks the options for a place shaped like this.
More on how this number was built
The methodology guide shows exactly how USFS turned 319 counted buildings into the percentiles shown above for Rio Oso. For more on what direct exposure implies beyond Rio Oso, see the exposure-zones guide.