C ▁( 7 3 ▁to ▁ 7 5   ° F ). ▁The ▁col dest ▁months ▁are ▁December ▁and ▁January , ▁with ▁average ▁temper atures ▁r anging ▁from ▁ 1 6 ▁to 1 7   ° C ▁( 6 1 ▁to ▁ 6 3   ° F ) ▁and ▁the ▁h ott est ▁month ▁being ▁July , ▁with ▁temper atures ▁over ▁ 2 9   ° C ▁( 8 4   ° F ). ▁The ▁average ▁annual ▁ra inf all ▁is ▁between ▁ ▁and ▁ ▁per ▁year , ▁divided ▁into ▁two ▁distinct ▁seasons : ▁there ▁ra iny ▁season ▁from ▁May ▁to ▁October , ▁and ▁the ▁non - ra iny , ▁or ▁less ▁ra iny , ▁season ) ▁from ▁November ▁to ▁February . ▁The ▁total ▁number ▁of ▁hours ▁of ▁sun light ▁per ▁year ▁aver ages ▁out ▁about ▁ 1 , 6 5 0 ▁to ▁ 1 , 7 0 0 ▁hours ▁per ▁year , ▁and ▁the ▁average ▁relative ▁hum id ity ▁is ▁ 8 0 ▁to ▁ 8 5 ▁per ▁cent . ▁Additionally , ▁being ▁next ▁to ▁the ▁G ulf ▁of ▁Ton kin , ▁Nam ▁ Đ ị n h ▁is ▁normally ▁affected ▁by ▁tropical ▁storm s ▁and ▁mon so ons , ▁with ▁an ▁average ▁of ▁four ▁to ▁six ▁attacks ▁per ▁year . ▁ ▁Econom y ▁In ▁ 2 0 0 0 ▁the ▁estimated ▁provincial ▁gross ▁domestic ▁product ▁reached ▁ 4 0 0 , 0 0 0 ▁United ▁States ▁dollars ▁( 5 . 9 2 ▁billion ▁ đ ồ ng s ). ▁In ▁