Weather systems in the tropics are the product of the largest reservoir of energy in the atmosphere — the deep, warm and moist tropical troposphere that extends, on occasions, beyond 16–18 km above the Earth’s surface. This warm air contains sufficient water vapour for condensation to provide an important additional energy source. Tropical climates are distinct from those of the mid-latitudes but it is increasingly realized that important interactions occur between the two climate systems. The best known of these is the influence of El Niño events on the weather and climate of many parts of the world. The aim of this chapter is to show how tropical climates are driven by thermal influences and how atmospheric and oceanic disturbances (e.g., El Niño events and tropical cyclones) shape the weather and climate of the tropics.