The U.S.-Affiliated Pacific Islands (USAPI) include three U.S. territories—American Samoa, Guam, and the Commonwealth of the Northern Mariana Islands—and three independent countries—the Federated States of Micronesia, the Republic of the Marshall Islands, and the Republic of Palau. The geology of the USAPI varies greatly—from volcanic high islands, to low coral atolls. Native ecosystems, traditional agricultural systems, hydrology, and interactions with the ocean are remarkably diverse. Droughts occur regularly and are often associated with El Niño events, which are part of a natural climate cycle in the Pacific Ocean.

The USAPI is vulnerable to the compound effects of climate change, including warming, changing drought conditions, and sea level rise, which contributes to saline contamination of freshwater supplies. Low atoll islands, where water supplies are limited to rainwater catchments, are particularly vulnerable to drought periods since water storage is often insufficient to sustain the local population. Drought in the USAPI can prompt Federal disaster declarations where residents are subject to mandatory water restrictions, and emergency deliveries of food, bottled water, and reverse osmosis pumps are required. Other impacts of drought include increased wildfire risk, negative public health and tourism impacts, loss of cultural practices, and reduced crop yields. Understanding the impacts of drought in the USAPI, summarizing the current state of the science, and improving resilience are important for successful adaptation and management.

NIDIS supports eight regional Drought Early Warning Systems (DEWS) throughout the United States. In addition, NIDIS supports states and territories outside these regions, like the USAPI, by delivering drought early warning information through Drought.gov; investing in drought research to address key scientific and societal needs; and supporting the development of new tools and products that serve the entire nation.