 Brinnon experiences an oceanic climate (Köppen climate classification "Cfb") and is almost categorised as part of the "Csb" climate category, receiving slightly more than , the threshold for "Cfb" inclusion.As of the census of 2000, there were 803 people, 413 households, and 258 families residing in the CDP.The population density was 81.3 people per square mile (31.4/km2).