CD P ) ▁in ▁Son oma ▁County , ▁California , ▁United ▁States . ▁F ult on ▁is ▁just ▁to ▁the ▁north ▁of ▁the ▁city ▁limits ▁of ▁Santa ▁Rosa , ▁and ▁ ▁north - n ortheast ▁of ▁Sebast opol . ▁F ult on ▁has ▁a ▁post ▁office ▁with ▁Z IP ▁code ▁ 9 5 4 3 9 , ▁which ▁was ▁established ▁in ▁ 1 8 7 1 . ▁The ▁community ▁is ▁named ▁after ▁Thomas ▁and ▁James ▁F ult on , ▁who ▁founded ▁the ▁community . ▁The ▁population ▁as ▁of ▁the ▁ 2 0 1 0 ▁U . S . ▁Census ▁was ▁ 5 4 1 . ▁There ▁are ▁a ▁set ▁of ▁railway ▁lines ▁which ▁go ▁through ▁the ▁town ▁boundaries ; ▁these ▁lines ▁are ▁used ▁by ▁Son oma – Mar in ▁Area ▁Rail ▁Trans it ▁( or ▁the ▁S MA RT ▁Train ). ▁ ▁History ▁ ▁The ▁community ▁is ▁named ▁after ▁Thomas ▁and ▁James ▁F ult on , ▁who ▁founded ▁the ▁community . ▁ ▁Geography ▁According ▁to ▁the ▁United ▁States ▁Census ▁Bureau , ▁the ▁CD P ▁covers ▁an ▁area ▁of ▁ 1 . 9   square ▁miles ▁( 5 . 0   km ² ), ▁all ▁of ▁it ▁land . ▁ ▁Cl imate ▁This ▁region ▁experiences ▁warm ▁( but ▁not ▁hot ) ▁and ▁dry ▁sum mers , ▁with ▁no ▁average ▁month ly ▁temper atures ▁above ▁ 7 1 . 6   ° F . ▁ ▁According ▁to ▁the ▁Kö ppen ▁Cl imate ▁Classification ▁system , ▁F ult on ▁has ▁a ▁warm - sum mer ▁Mediter