All life relies on the availability of water. Knowing when, where, and how much it rains or snows is vital to understanding how weather and climate impact our environment, and in turn human society. The movement of water and energy around Earth affects agriculture, fresh water availability, and the occurrence of natural disasters.
In many parts of the world, rain is the only source of water for both drinking water and agriculture. Rain also recharges ground water aquifers, and spring snowmelt replenishes rivers and streams for the summer. Having too much or too little water often results in natural disasters for populations around the world, where tropical cyclones, floods, droughts, and landslides can wreak havoc on local communities. Having accurate information on rain and snow is critical for estimating when to plant crops, where to build houses, how to plan transportation routes, and to what extent we need assistance during extreme weather.