Pacific typhoons generally develop to the east of the Marshall Islands area but the RMI is only occasionally subjected to the full brunt of a Pacific typhoon.  The northern atolls are more subject to typhoons than are the southern atolls.  The storms (sustained winds of 40-74 mph/64-119 km/h) impact the atoll about once every four to seven years on average, corresponding to El Niño-Southern Oscillation events that warm the ocean waters and provide conditions for the genesis of cyclones.  An analysis of the historic record of typhoons in the Marshall Islands has identified a significant association between the occurrence of ENSO and the occurrence of typhoons in the Marshall Islands [6]. While typhoons normally occur further to the west, the warming of the ocean waters around the Marshall Islands, as part of the ENSO phenomenon, spawns typhoons further to the east. The results of the statistical analysis suggest that typhoons are 2.6 times more likely to occur during ENSO years, with a 71% chance of a typhoon or severe tropical storm striking during an ENSO year, and only a 26% chance of one happening during a non-ENSO year [5, 6]. Much more common are minor storms of the easterly wave type, especially from March to April and October to November [1].

Due to the long distance from north to south, rainfall varies greatly throughout the Marshall Islands.  In the wet, southern atolls, rainfall is heavy and can average as much as 160 inches (1,524 mm) per year, while the dry, northern atolls may only average 20 inches (508 mm). There is also a wet and dry season, with the wettest months being between May and November [1].  In 2007, the total rainfall at the Majuro Weather Station was 119 inches (3,014 mm), 13 inches (330 mm) less than the normal annual amount measured between 1970 and 2000. In Kwajalein, it was 89 inches (2,261 mm), also 11 inches (279 mm) less than normal [3].

Marshall Islands canoes. Source: C. Anderson, 2006. Local canoes line the main lagoon in Majuro, where all shipping operations occur, including delivery of imported goods and fisheries operations that bring in large revenues for the government during ENSO events.

The Marshall Islands are historically referred to in folklore as "jolet jen Anij" (gifts from God). A God-given sanctuary away from the harshness of other areas is therefore part of the socio-cultural identity of the people. However, they are now often referred to as a "front line state" with regard to the climate change issue. The country has suffered inadequate supplies of potable water as a result of ENSO related events.  Moreover, the Marshall Islands lie in open ocean and the average height above sea level of its 1,225 islets in 29 atolls is only 7 feet (2 meters).  Fragile coral reefs fringe the atolls, and serve as the only line of defense against the ocean surge. The clearance over the reef in the sections that are covered by water is usually no more than a couple of feet. Given the physics of wave formation and the increasing frequency and severity of storms, the Marshall Islands will likely be at even greater risk. It is likely that evacuation would have to be effected long before inundation is total.  The Marshallese would become among the first of many environmental refugees [1].

Namorik, Marshall Islands. Source: NASA 2001. Namorik is a small and isolated atoll located to the southwest of Jaluit Atoll. The formation consists of two large islets that enclose a small lagoon of 8.4 km². The largest of the islets (also called Namorik) wraps around the lagoon from the southwest to the northeast; the smaller island occupies the northwest corner of the atoll. They have a combined land area of 2.8 km².