This study evaluated whether neighborhood-level disorder, social cohesion, and perceived safety, were associated with days of cannabis use in the prior month in a representative sample of young adults in Alameda and San Francisco Counties in California (N = 1272). We used multiscale geographically weighted regression, modeled by county, to measure associations between cannabis use days and neighborhood attributes, adjusting for sociodemographic characteristics and self-rated health. Positive associations were found between number of cannabis use days and neighborhood disorder, and greater perceived safety. Higher levels of social cohesion predicted fewer cannabis use days. Racial/ethnic, sex and, socioeconomic compositions of participants residing in areas with significant neighborhood-level associations varied substantially, suggesting that risk factors for young adult cannabis use may be highly localized. Public health efforts in cannabis education and intervention should be tailored to fit the culture and composition of local neighborhoods.