The objective of this work is to show the characterization and the variability of the climate of the Paraíba Valley between 1946 and 1995, which is considered one of the most important regions of the country in political, economical and industrial terms. The data that will be presented aims to form a climatological database to facilitate regional planning to support socio-political, tourist and industrial decisions. In the 70's, there was a great industrial growth due to the implementation of numerous industries and companies in various fields of activity. This fact certainly contributed directly to changes in the physical conditions of the local atmosphere and the microclimates of the region. Large scale dynamic/synoptic analyses were performed over South America and the Paraíba Valley. Temperature, Precipitation, Relative Humidity and Wind Speed/Direction data were also collected. A study of the frontal systems that acted over the region. The climate of the Paraiba Valley is a humid mesothermal climate with drought in the winter season and rain in the summer season. The Atlantic Subtropical High plays a more important role acting throughout the year.