exceeded the 50-year return period, during October 1996 and October 1998, which suggest an increase in heavy rainfall along the coast. Pacific islands Hawaii Snow, although not usually associated with tropics, falls at higher elevations on the Big Island, on Mauna Loa as well as Mauna Kea, which reaches an altitude of , in some winter months. Snow only rarely falls on Maui's Haleakala. Mount Waiʻaleʻale (Waialeale), on the island of Kauai, is notable for its extreme rainfall, as it has the second highest average annual rainfall on Earth, with . Storm systems affect the state with heavy rains between October and March. Showers are common across the island chain, but thunderstorms are relatively rare. Local climates vary considerably on each island due to their topography, divisible into windward (Koolau) and leeward (Kona) regions based upon location relative to the higher mountains. The Kona coast is the only area in Hawaii with a summer precipitation maximum. Windward sides face the east to northeast trade winds and receive much more rainfall; leeward sides are drier and sunnier, with less rain and less cloud cover. In the late winter and spring during El Niño events, drier than average conditions can be expected in Hawaii. Northern Marianas The islands have a tropical marine climate moderated by seasonal northeast trade winds. There is a dry season which stretches from December to June, and a rainy season from July to November. Saipan's average annual precipitation is , with 67 percent falling during the rainy season. Typhoons frequent the island chain, which can lead to excessive rainfall. Guam Guam's climate is moderated by east to northeast trade winds through the year. The average annual rainfall for the island is . There is a distinct dry season from January to June, and a rainy season from July to December. Typhoons frequent the island, which can lead to excessive rainfall. During El Niño years, dry season precipitation averages below normal. However, the threat of a tropical cyclone is over triple what is normal during El Niño years, so extreme shorter duration rainfall events are possible. American Samoa American Samoa's climate regime is dominated by southeast trade winds. The island dependency is wet, with annual rainfall averaging near at the airport, with amounts closer to in other areas. There is a distinct rainy season when tropical cyclones occasionally visit between November and April. The dry season lasts from May