▁and ▁Sh ib ata , ▁with ▁a ▁small ▁coast line ▁on ▁the ▁Sea ▁of ▁Japan . ▁ ▁S urr ounding ▁municipal ities ▁Ni ig ata ▁Pref ect ure ▁K ita - ku , ▁Ni ig ata ▁Sh ib ata ▁ ▁Cl imate ▁Se ir ō ▁has ▁a ▁Hum id ▁climate ▁( K ö ppen ▁C fa ) ▁character ized ▁by ▁warm , ▁wet ▁sum mers ▁and ▁cold ▁winter s ▁with ▁heavy ▁snow fall . ▁ ▁The ▁average ▁annual ▁temperature ▁in ▁Se ir ō ▁is ▁ 1 3 . 1   ° C . ▁The ▁average ▁annual ▁ra inf all ▁is ▁ 1 9 4 0   mm ▁with ▁September ▁as ▁the ▁wet test ▁month . ▁The ▁temper atures ▁are ▁highest ▁on ▁average ▁in ▁August , ▁at ▁around ▁ 2 6 . 3   ° C , ▁and ▁lowest ▁in ▁January , ▁at ▁around ▁ 1 . 5   ° C . ▁ ▁Dem ograph ics ▁Per ▁Japanese ▁census ▁data , ▁the ▁population ▁of ▁Se ir ō ▁has ▁grown ▁slightly ▁over ▁the ▁past ▁ 4 0 ▁years . ▁ ▁History ▁The ▁area ▁of ▁present - day ▁Se ir ō ▁was ▁part ▁of ▁ancient ▁E ch igo ▁Province . ▁After ▁the ▁Me iji ▁rest oration , ▁the ▁area ▁was ▁organized ▁as ▁part ▁of ▁Kit ak an bara ▁District , ▁Ni ig ata . ▁The ▁village ▁of ▁Se ir ō ▁was ▁established ▁on ▁April ▁ 1 , ▁ 1 8 8 9 ▁with ▁the ▁creation ▁of ▁the ▁modern ▁municipal ities ▁system . ▁It ▁was ▁raised ▁to