Based on hydrometeorological data from 1960 to 2020, this study systematically analyzed the abrupt changes and monthly-scale variations in runoff depth, precipitation, temperature, potential evapotranspiration, and snow characteristics in the Yangtze River Source Region from 1960 to 2020, employing methods such as the Pettitt non-parametric test and simple linear regression. The results showed that during 1960-2020 in the Yangtze River Source Region, the multi-year average annual runoff depth was 90 mm, which shifted from a declining trend to an increasing trend after 2004. Annual precipitation exhibited a mutation in 1997, increasing at a rate of 0.54 mm/a before the mutation and slightly decreasing thereafter. The mean annual temperature was -4.5℃, with the warming rate accelerating from 0.02℃/a before 1997 to 0.05℃/a afterward, significantly higher than before. Potential evapotranspiration showed an overall increase, with a 6% rise after the mutation. The multi-year average snow depth was 1.7 cm, showing a decreasing trend, with a rate of 0.1 cm/a. At the monthly scale, runoff depth and precipitation showed significant seasonal fluctuations, with summer accounting for over 60% of the annual contribution. Winter temperatures showed the largest increase, exhibiting a typical “cold-season amplification effect”. The multi-year average aridity index was 1.8, showing a downward trend, reflecting the regional climate’s transition towards humidification. The multi-year average runoff coefficient was 0.2, decreased before 2004 and then rebounded, reflecting the increased complexity of hydrological processes due to factors such as snow melting and groundwater recharge.