Question

Why is the convectional rainfall in the Amazon basin also known as 4 o’clock rainfall?

Answer 1

The convectional rainfall in the Amazon basin is also called the “4 o’clock rainfall” because it usually occurs in the afternoon, around 4 PM.

• During the day, the land surface heats up due to the Sun's intense rays.
• This causes the air near the surface to heat and rise rapidly in convection currents.
• As the hot, moist air rises, it cools, condenses, and forms clouds.
• By around 4 PM, these clouds become heavy and cause heavy rainfall.
• This type of rainfall is typical in equatorial regions like the Amazon and happens almost daily.

Hence, this afternoon rainfall is popularly known as “4 o’clock showers” or “4 o’clock rainfall.” It is accompanied by thunder and lightning and is a type of convectional rainfall caused by intense surface heating and rapid upward air movement.