The content provided in this book was taken from the Master's thesis conducted between 2009 and 2011, whose subject on climate change has been widely discussed over the past three decades worldwide. Unexpected meteorological phenomena have happened in several countries whose historical series have shown values far above average, as is the case of floods in desert areas of Saudi Arabia that rained in three days, the volume expected for several years or the drought of famous lakes in California in the United States without the presence of rain for long periods. Some changes were found for the city of Recife, the study site, State of Pernambuco/Brazil in the Maximum and Minimum Compensated Temperature, Precipitation and for Relative Humidity. Probably, these changes can be related to the frequent occurrences of El Niño and La Niña phenomena.