Over what area is rainfall measured?

Question

When they say it has rained 10mm, how do they measure this and do they have more than one location that it gets measured.

Answer 1

Rain is measured using a rain gauge....

A rain guage is simply a funnel which gathers rain drops as they land in it, and stores then inside a cylindrical tube. This tube is know as a primary reservior. It is usually notched or marked so you can measure the amount of rain that has fallen. This primary reservior sits inside of the overflow reservior and the fullel neatly rests on the enge of the overflow, as if it were a lid, sealing it off on the edges.

As rain fills the primary reservior, it overflows into the overflow reservior.

Whne it is time to measure the total rainfall, the primary is measured, and if full it is emptied and the overfolw is then dumbed into the primary to measure that. Rinse and repeat until all rainfall is measured.

Answer 2

Rain is measured anyplace you place a rain gauge. It can be at an official site, such as the National Weather Service in your area, or even your own back yard.