Indonesia’s climate is largely hot and humid, with rainfall occurring mostly in low-lying areas and mountainous regions experiencing cooler temperatures. The cities of Jakarta, Ujung Padang, Medan, Padang, and Balikpapan have an average minimum temperature of 22.8°C and a high of 30.2°C. Humidity in Jakarta varies between 61% to 95% and average rainfall amounts to 218.4 millimeters (mm) per month. The “wet” season occurs between November and April, leaving May through October typically dry. Indonesia experiences drier conditions during El Nino events and wetter conditions during La Nina events. Indonesia lies across the range of the Inter-Tropical Convergence Zone (ITCZ) where the northeast and southeast trade winds penetrate the doldrums. Strong ascending motion, overcast skies, strong squalls, heavy rainfall and severe local thunderstorms with variable intensities are characteristics of this zone.