Shenzhen city, located in southern China and governed by the East Asian monsoon climate system, has experienced rapid urbanization since the beginning of the 1980s, and had become an international metropolis by the 2010s. Urban-induced changes in rainfall of various intensity grades over Shenzhen are investigated using nested numerical integrations at 3.3 km spatial resolution, within which urban surface distributions and expansions are well represented by satellite-based data. The urban-induced impact on subregion average of daily rainfall (DRAIN) and cumulative volumetric rainfall (VRAIN) intensity and variability, as well as rain areas and number of rain days, are evaluated. For total rainfall amounts, significant changes are only detected in VRAIN and DRAIN variability on seasonal scales. However, for different intensity grades of rainfall, urban-induced changes in VRAIN and DRAIN intensity and variability of both annual and seasonal results are more pronounced. Significant changes are detected only for heavy storm rain on annual scales, whereas marked subregional characteristics are found for various grades of rainfall on seasonal scales. The increased DRAIN/VRAIN intensity and variability for heavy storm rain due to urban surface expansion from the 1980s to the 2010s can be linked to intensified vertical circulation and changes in moisture flux. A reduced local evaporation-related moisture flux and a weakened southeasterly water vapor transport result in a decreased relative humidity in the near-surface layers. However, an intensified southwesterly moisture flux induces an increased relative humidity in the low-middle troposphere.