Abstract
The Metropolitan Region of Baixada Santista (MRBS) holds significant economic importance for both the state of São Paulo and Brazil as a whole. This study provides detailed information on total and extreme rainfall events, as well as the ongoing changes affecting the region. To this end, trends and magnitudes of extreme precipitation events were analysed using the Mann‐Kendall test and Sen's slope estimator, respectively, at a 95% confidence level. To assess the intensity and frequency of these extremes, climate indices were employed. Anomalies during the dry and wet seasons were also examined to understand current rainfall behaviour relative to historical patterns, using established variables. The aim was to interpret the meteorological dynamics over the region. Results indicate that the central and northern sectors of the MRBS are the most vulnerable to extreme rainfall events. The number of consecutive wet days and consecutive dry days showed a statistically significant positive trend. The 5‐day accumulated precipitation values exhibited positive trends, particularly in the central portion of the MRBS during the wet season. These extreme rainfall events are potential triggers for landslides and floods in the region, and their increasing intensity could lead to hydro‐geo‐meteorological disasters in exposed and vulnerable areas. These trends are consistent with the observed increase in Sea Surface Temperature (SST) in the South Atlantic and with enhanced activity of low‐pressure systems in the region, especially during the wet season.