The summit of Waiʻaleʻale features a tropical rainforest climate, with substantial rainfall throughout the course of the year quotes 11,684 millimetres (460.0 in) per year figure as being the 1912-45 average, an average that quite possibly will have changed since then, while The National Climatic Data Center quotes this figure as a 30 year average. The Weather Network and The Guinness Book of Weather Records (Holford 1977: 240) quotes 11,455 millimetres (451.0 in) rain per year, while (Ahrens 2000: 528) quotes 11,680 millimetres (460 in, 12 m) as the average annual rainfall at Mount Waialeale and claims 13,000 millimetres (510 in) falls here. Similarly, The Weather Network and the Guinness Book of Weather Records quote 335 days with rain here suggests that rain falls on an incredible 360 days per year here.
The local tourist industry of Waialeale has promoted it as the wettest spot, although the 38-year average at Mawsynram, Meghalaya, India, is higher at 467.4 inches (11,870 mm). Both Mawsynram and Cherrapunji in Meghalaya are recognized by the Guinness Book of World Records as having higher average rainfall. Mawsynram's rainfall is concentrated in the monsoon season, while the rain at Waiʻaleʻale is more evenly distributed through the year.