Hawaii has a tropical climate cooled by trade winds. Normal daily temperatures in Honolulu average 72°F (22°C) in February and 78°F (26°C) in August; the average wind speed is a breezy 11.3 mph (18.2 km/hr). The record high for the state is 100°F (38°C), set at Pahala on 27 April 1931, and the record low is 12°F (–11°C), set at Mauna Kea Observatory on 17 May 1979.
Rainfall is extremely variable, with far more precipitation on the windward (northeastern) than on the leeward side of the islands. Mt. Waialeale, Kauai, is reputedly the rainiest place on earth, with a mean annual total of 486 in (1,234 cm). Kukui, Maui, holds the US record for the most precipitation in one year—739 in (1,878 cm) in 1982. Average annual precipitation in Honolulu (1971–2000) was 18.3 in (46.5 cm). In the driest areas—on upper mountain slopes and in island interiors, as in central Maui—the average annual rainfall is less than 10 in (25 cm). Snow falls at the summits of Mauna Loa, Mauna Kea, and Haleakala—the highest mountains. The highest tidal wave (tsunami) in the state's history reached 56 ft (17 m).