how does it rain | why does it rain | rain diagram

Did you know?

All rain starts with the sun.

Did you know?

There are places in the Atacama desert which haven't seen rain for 400 years.

How it rains.

  1. The sun heats up the air.

  2. Warm air rises.

  3. As the air rises, it cools.

  4. The water vapour held in the air condenses back into water. If the air rises far enough, the water vapour might turn into ice crystals.

  5. If enough condensation occurs, a cloud will form, which is made up of billions and billions of little drops of water.

  6. Eventually the water held in the air becomes too heavy to be held up by rising currents of air and it falls to the ground as rain, or snow, if it is really cold. 

Geography topics for you to learn and enjoy

Definition of rain

The condensed moisture of the atmosphere falling visibly in separate drops. 

Synonyms for rain

Rainfall, precipitation, rain drops, wet weather, sprinkle, drizzle, mizzle, scotch mist, shower, rainstorm, cloudburst, torrent, downpour, deluge, squall, thunderstorm

Heavy
rainfall

Types of rain

There are three main types of rainfall: convectional rain, frontal rain and relief rain.

 

Rain is formed when air rises and so there are three ways of making air rise: by going over a mountain (relief rain), by rising through to being heated by the sun (convectional rain) and a warm body of air rising over a cold body of air (frontal rain). 

types of rainfall | relief rain diagram
Relief rain
types of rainfall | convectional rainfall diagram
Convectional rainfall
types of rainfall | frontal rain diagram
frontal rain

Rainfall facts

Wettest place on earth

In 1985, the Khasi Hills region of Meghalaya State in India received 26,000 mm of rain. A world record. 

Rainfall facts
  • Rain drops can vary in size from 0.5 mm across to 8 mm across.

  • Rain falls to the ground at 35 km an hour.

  • Antarctica is the driest continent on Earth.

  • Heavy rain can cause flooding and landslides

Driest place on Earth

There are parts of the Atacama desert which have never recorded rain. 

  • The most rain to fall in one day fell during a hurricane.

  • Rain can mix with pollutants in the air to form Acid rain and this is harmful to wildlife.

  • Water can fall as rain, as sleet, as snow or as freezing rain.

Measuring the rain

heavy rain

How do we

measure the rain?

We measure the rain using a rain gauge.  It measures the rain over a set period of time. 

 

What do we measure

the rain with?

Modern rain gauges are self recording and automatically measure the rain in 5 minute intervals. This rain gauge is solar powered for working out in rural areas.

how to measure the rain

Freezing rain

Freezing rain
Freezing rain

Cause

Freezing rain is super cooled rain that freezes on impact. Helped along by the fact that the ground is also below freezing.

Effects

This rare event can be costly and create a lot of damage. Pulling down electricity wires and telephone wires and making roads extremely dangerous is the biggest headache caused by freezing rain.

WHY DOES IT RAIN?

Here we look at how rain forms and at the different types of rain that there are. From relief rain, frontal rain and convectional rain, we see what conditions are needed to make rain. We go on to look at how you would measure rain with a rain gauge and some of the more extreme rainfall events like freezing rain and raining frogs! Packed full of pictures of rain, this page has all you need to know about rain.