The increase in the average temperature of the planet can cause changes in rainfall regimes, deregulate the water capacity of a region, aggravate health problems in the population and cause economic losses. Analyzing sites that are undergoing a meteorological trend makes it possible to estimate the possible detriments of these changes in socioeconomic activities. Thus, we investigated temporal trends in historical series for precipitation and average temperature between 1962 and 2017 in the city of Parnaiba, Piauí. Rainfall data were compiled from the National Institute of Meteorology and the National Water Agency, obtaining maximum annual rainfall and average temperatures, for the classification of extreme events linked to precipitation was applied the Quantis technique. The averages over the years 1964, 1974 and 1985 were the rainiest of the series, referring to three peaks of flood (high precipitation). The years 1988 and 1991 were categorized as "very rainy". On the other hand, 1998-2017 were the driest years, presenting the highest numbers of drought, during which period the increase of fires occurred in Piaui. It can be concluded that droughts are longer, resulting in water reduction, and as soon as the climatological trends for the city exist, it is suggested that we can consider them as impacts of global climate change.