Uruguay is the only South American country situated completely in the warm zone.

The absence of important geographic systems contribute so that the horizontal variation of temperature, raining and other climate items are very little. Within the oceanic factors, the presence of the warm current from Brazil produce an inestability of the low capes of the atmosphere with an important contribution of temperature and humidity in the coast zones.

The cold current of Malvinas generate a stability and a coldness of the air masses as that surround above it. The anticiclon semipermanente of the Atlantic influence on the development of the weather in Uruguay. The horizontal circulation originated establish that the direction of the wind is mainly from the northeast to east, bringing masses of air of tropical origen.