There are many factors that determine the climate of a certain area of the world. These factors are the main things that determine how much rain and snow will fall on certain places. These factors include the temperature, the geographical location of the area on the globe, its height above the sea level, the positioning of mountain ranges and so on.
The wettest or rainiest place on earth is at Mount Waialeale, on the island of Kauai, Hawaii. This place receives an average amount of rainfall every year of 475 inches of rain. The second spot is located on Cherrapunji, Indiawho receives an average yearly rainfall of about 450 inches of rain. In fact there is a year that the rain fell on this place for 5 days non-stopped that it poured out more than 150 inches of rain. And in 1861, this place receives a total amount of 905 inches of rain in just one year.
You might wonder how much rain the above places receive; here is some comparison to some famous places on earth:
- New York City gets an average rainfall of about 40 inches per year;
- San Francisco gets an average rainfall of about 20 inches per year;
- Boston City gets an average rainfall of about 42 inches per year;
- Chicago gets an average rainfall of about 30 inches per year;
- Ottawa, Canada gets an average rainfall of about 34 inches per year;
- Madrid, Spain gets an average rainfall of about 17 inches per year;
- Paris, France gets an average rainfall of about 22 inches per year
With this comparisons, you can now is the contrast of 475 and 450 inches of rainfall in Mount Waialeale and Cherrapunji receives per year.
For the driest place in the world which is probably belonging to Arica, Chile. The average rainfall this place receives per year is only about 0.02 inches. While in United States, the driest place is located at Greenland Ranch, Death Valley which only receives about 1.5 inches of rainfall per year.
Tropical countries which belong or near the equator receives heavy rainfall every year. This rainfall had an average of 60 inches or more depending on the topography of the place. Why these countries on or near the equator do receives this amount of rainfall? This is because the equator is the meeting point of large stream of air masses; the air moving down to it from the north meets the air moving upward from the southern part of the equator. One part of these two air currents is hot while the other is colder. When the two air masses meets, large amounts of water vapor condenses (preferably those on the hot air) to form rain drops in the clouds.