The climate varies considerably within the national park. The prevalent wind direction for most of the year is west to east, leading to cloud formation on the upper slopes of the Fansipan massif. These high-altitude areas are covered by cloud most days of the year and have very high humidity. Cloud also penetrates into the valleys but these areas are usually less humid than the mountain slopes. In the extreme east of the national park, around Ban Ho village, mean temperatures are considerably higher due to the lower altitude of these areas.