Convectional or convective rainfall occurs due to thermal convection currents caused by insolation heating of the ground surface. Orographic rainfall occurs due to the accent of air from highland. Cyclonic or frontal rainfall occurs due to upward movement of air caused by convergence of contrasting wind. In equatorial regions, convectional rain occurs almost daily in the afternoons. It generally occurs at 4 pm that why it is known as 4o Clock Rain.

The rising warm air cools and condenses, forming cumulus clouds. This results in a rainfall known as convectional rainfall. The equatorial region receives convectional rainfall during the afternoon on a daily basis. The rainfall happens around 4 p.m, and is known as “4 o'clock rainfall”. 4 o'clock rainfall is a correct answer because 4 o'clock rainfall as the convectional rainfall which is experienced by the Amazon River basin every afternoon. A convectional rainfall occurs when the energy of the sun heats the surface of the earth, causing water to evaporate and form water vapour. Lowlands on either side of the equator, the Congo Basin, the coast of the Gulf of Guinea, the Amazon basin, and coastal Kenya all have a 4 o'clock rain sort of climate. 4 o'clock showers' are caused by convection currents. The cooling causes condensation, which results in heavy downpours. This rain is accompanied by thunder and lightning and since it mostly occurs around 4 p.m., it is often called the 4 o'clock showers'.Conventional rainfall occurs generally in the equatorial regions of the world. Other regions of convectional rainfall are middle latitudes on summer days. Most of India's rainfall is brought by southwest monsoon winds but you can also observe conventional rains in India, during hot summers in places like Delhi, Andhra Pradesh etc. When the sun's energy heats the Earth's surface, water evaporates and becomes water vapour, causing convectional Precipitation. Convectional or convective rainfall occurs due to thermal convection currents caused by insolation heating of the ground surface. Orographic rainfall occurs due to the accent of air from highland. Cyclonic or frontal rainfall occurs due to upward movement of air caused by convergence of contrasting wind. Convectional rainfall is a type of rainfall that involves the formation of convection currents. The cyclonic rainfall, on the other hand, is caused due to cyclones. A cyclone has a warm front and a cold front with a substantial difference in the temperatures. Convective precipitation is generally more intense, and of shorter duration, than stratiform precipitation. Orographic precipitation occurs when moist air is forced upwards over rising terrain and condenses on the slope, such as a mountain. The types of rainfall based on intensity can be classified as: Light rain Rate of rain varies between 0 to 2.5 millimeters. Moderate rain Rate of rain varies between 2.6 millimeters to 7.6 millimeters. Heavy rain Rate of rain is beyond 7.6 millimeters.