In boreal summer, the Asian monsoon circulation carries abundant water vapor from the Indian Ocean to the lower–middle troposphere in the Himalayan region. This creates conditions favorable for some of the heaviest orographically induced precipitation in the world over the steep and topographically complex southern slopes of the Himalayas. Here, we introduce summer precipitation variability, including extreme events over the Himalayas, and its dynamics based on studies using in situ observations, spaceborne precipitation radar, and cloud-resolving numerical models. Specifically, we focus on the diurnal cycle, low pressure systems (LPSs), intraseasonal oscillations (ISOs), and their interplay, which represent an important background environment for extreme precipitation events in the Himalayas. In the diurnal cycle of precipitation, twice-daily precipitation maxima corresponding to daytime and nighttime peaks occur across higher elevations, while a single peak appears at night over lower elevations. The daytime peak is the result of anabatic flow driven by surface heating of the slopes, whereas the nighttime peak is caused by acceleration of low-level monsoon flows (i.e., the nocturnal jet) from the Gangetic Plain toward the Himalayas. Additionally, LPSs such as monsoon lows and monsoon depressions, together with mid-latitude troughs and their interaction can modulate strong inflows of moisture toward the Himalayan slopes, occasionally leading to extreme precipitation events when the flow with abundant water vapor is forced to ascend over the Himalayan slopes. The locations of the LPSs and mid-latitude troughs are strongly controlled by ISOs that act as large-scale environmental conditions for the genesis and development of the LPSs and troughs. Thus, improved understanding of the controlling multiscale processes, including the diurnal cycle, is essential for better prediction of extreme precipitation events and mitigation of related disasters over the Himalayas.