# How do you know how much rain has fallen?

### How do you know how much rain has fallen?

To measure the heights of precipitation (we also speak of “precipitation blades”), a rain gauge is used, the principle of which is simply to channel the precipitation to measure its volume or mass (manually or automatically). The unit used is the mm (millimetre) or L/m².

### Where should the rain gauge be placed?

the rain gauge must be installed between 0.5 and 2 meters from the ground, on flat ground, far from any shelter or wall, and in as open a space as possible. The presence of nearby trees is detrimental to the proper functioning of the rain gauge because their branches can deflect precipitation.

### How to interpret the weather forecast?

When the risk of precipitation is below 70%, showers are expected, concludes Mr. Robert-Lacroix. When the percentage is higher, it means that rain is expected, which will affect a larger area and could fall for longer.

### How to install netatmo rain gauge?

Site. the rain gauge must be placed horizontally, if possible raised cm from the ground, and at a distance equal to the height of the surrounding obstacles (by default 3m).

### Is 4mm of rain a lot?

This measurement corresponds to the height of water collected on a flat surface. It is expressed in millimetres, and sometimes in liters per square meter (1 litre/m2 = 1 mm ). We separate the intensity from the rain in rain low (trace at 2 mm/h ), moderate (2 mm/hr at 7.6 mm/h) and strong (more than 7.6 mm/h).