Why is rainfall seasonal?

Answer 1

Rainfall or indeed weather is driven by the heat form the Sun falling on the Earth. However the Earth spins on its axis with this axis inclined some 23.5 degrees from the normal to plane in which it orbits the Sun. This means that over the year the position at which the Sun is directly overhead on the planet moves North and South 23.5 degrees either side of the Earth's equator. This movement drags the heating effect of the Sun with it, and hence the weather systems and rainfall are seasonal.

Answer 2

Rainfall is seasonal because it is influenced by factors such as the tilt of the Earth's axis, the movement of air masses, and the position of the sun. These factors create patterns in precipitation that vary throughout the year, leading to the seasonal distribution of rainfall in different regions.