Climate The overall climate of New Zealand is influenced by the mountains and the ocean. Although its northern reaches enjoy a temperate climate,weather can change quickly across the country,because the tropical cyclones travel through region of the South Pacific frequently.New Zealand is located in the Southern Hemisphere,so the warmest months are December,January,February;the coldest are June,July and August.Climate The overall climate of New Zealand is influenced by the mountains and the ocean. Although its northern reaches enjoy a temperate climate, weather can change quickly across the country, because the tropical cyclones travel through region of the South Pacific frequently. New Zealand is located in the Southern Hemisphere, so the warmest months are December, January, February; the coldest are June, July and August