What climate patterns shape rainfall in the Federated States of Micronesia?

Rainfall in the Federated States of Micronesia is significantly influenced by large-scale atmospheric and oceanic climate patterns, most notably the El Niño-Southern Oscillation (ENSO).12

• El Niño-Southern Oscillation (ENSO): This system, which fluctuates irregularly every two to seven years, is a primary driver of rainfall variability. During El Niño events, the westward-moving trade winds weaken, which can lead to drier conditions in the western Pacific, including Micronesia. Conversely, La Niña events typically amplify these trade winds, often resulting in increased precipitation across the region.2
• Intertropical Convergence Zone (ITCZ): This belt of converging trade winds and rising air encircles the Earth near the Equator. As it shifts north and south seasonally, the ITCZ plays a critical role in generating heavy rainfall and frequent thunderstorms in tropical regions like Micronesia.3
• Extreme Weather: The region is also subject to intense weather events, including typhoons, which can cause significant flooding and destruction, as well as prolonged droughts during certain ENSO phases.1