Elevation‐Dependent Variations of Summer Precipitation on the Southern Slopes of the Central and Eastern Himalayas

Abstract Precipitation patterns in the Himalayas vary in complex ways with elevation but remain poorly understood due to limited in situ data. In this study, we present observations from two rain‐gauge networks spanning different elevations established in the Yarlung Tsangpo Grand Canyon and the Khumbu Valley. Using these ground‐based data, we provide the first comparative investigation of summer precipitation variation along elevation gradients in the Central and Eastern Himalayas. In both regions, precipitation increases with elevation up to a peak and then decreases between 1,500 and 4,300 m above sea level. A marked precipitation maximum occurs near 2,500 m above sea level, largely induced by frequent heavy precipitation events (≥1 mm hr −1 ). The diurnal cycle of mean precipitation generally displays a consistent unimodal pattern, with a daytime minimum and a nighttime maximum. However, the diurnal variation exhibits distinct afternoon differences with elevation in the Central and Eastern Himalayas: an afternoon secondary peak in precipitation is discernible at low‐ and mid‐elevation sites in the Central Himalaya, which is absent in the Eastern Himalaya. The former is primarily associated with ridge convection triggered by afternoon upslope flow, whereas the latter is suppressed by the descending branch of local mountain circulation driven by convection at high elevations.