Atmospheric tides are studied based on barometric pressure data, registered on the CIOH automatic meteorological station during the period between August 2007 and July 2008. Even though daily variation of the atmospheric pressure in the tropics is higher than in upper latitudes, there exists a common opinion that the influence of atmospheric tides on the weather is negligible. Nevertheless, the analysis of rain events along different phases of the tide shows an influence of such tides over the evolution of tropical waves and precipitation associated with them. The explanation of this phenomenon lies on the presence of amphidromic systems in the atmospheric tides, induced by the oceanic ones.