Turbulence and wind shear reported by pilots during landing and taking-off procedures at the São International Airport (SPIA) are analyzed together with instability indexes and weather radar derived variables. The SPIA is one of the most important airports in Brazil with more than 13 million passengers a year. All instability indexes (K, SI, Windex, DQE, G, CAPE and the bulk Richardson number) were estimated from daily soundings in the region and cloud echo tops, rainfall rates and gust speeds estimated with the reflectivity data measured with the São Paulo weather radar (SPWR) for the summers between 1994 and 1999. Results show that 80% of all turbulence and wind shear events reported by pilots were associated with Cumulunimbus cells. Furthermore, strong downdrafts as indicated by Windex and DQE indexes agree well with observed areas of strong gust winds. It is shown that these two indexes and the variables derived from the SPWR can be used to predict and to detect turbulence and wind shear. Finally, the SPIA operations is often affected by the more frequent ordinary cells.