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**Cm**, it is one

**cm rainfall**. Tomeasure accurately, a measuring glass of

**1**/10 th base areaof the

**rain**gauge will be used. So

**1 cm**will go up toa height of 10

**Cm**but will be calibrated as only

**1Cm**.

Herein, what does 1 cm rain mean?

The "length", or more accurately, "depth" being measuredis the depth of **rain** water that **would** accumulate on aflat, horizontal and impermeable surface during a given amount oftime, typically an hour. One millimeter of **rainfall** is theequivalent of one liter of water per square meter.

**rain**= Depth x radius x radius x 3.14.Find the area at the top of the bucket (this is the area over whichthe

**rain**is collected). Divide the

**rainfall**volume bythis area to get the

**rainfall**.

Also asked, how much rain is a lot mm?

Moderate **rain**: Greater than 0.5 **mm** perhour, but less than 4.0 **mm** per hour. Heavy **rain**:Greater than 4 **mm** per hour, but less than 8 **mm** perhour. Very heavy **rain**: Greater than 8 **mm** per hour.Slight shower: Less than 2 **mm** per hour.

Forecast **means** prediction of a future event.Therefore, it may or may not take place. **2 mm** of**rainfall** on weather forecast **means** that there is apossibility of **rainfall** having a depth of **2 mm**. Here,**mm** is the unit of **rainfall** measurement, thatrepresents the amount of ponded water on a flat surface ifcollected.