Abstract: During the 2025 rainy season, South Asia and Southeast Asia were hit by widespread and persistent heavy rainfall, with river basin floods, flash floods, urban waterlogging and other disasters triggered. These disasters caused casualties and severely disrupted local economic and social development. In South Asia, countries such as India, Pakistan and Nepal recorded precipitation far year-round level. The death toll from floods in Pakistan during the entire rainy season reached 750. In Mumbai, India, severe inundation resulted in local traffic paralyzing. Torrential rains in Nepal resulted in 41 deaths and 121 injuries. Many countries in Southeast Asia also faced severe impacts. Sustained heavy rainfall in Malaysia led to floods, forcing over 10 000 residents to evacuate urgently. Extreme rainfall hit multiple regions in Vietnam, leading to river basin floods and urban waterlogging. The disasters in these regions destroyed 8 km of flood-control embankments and inundated 15 villages. They also affected 50 000 hm2 of farmland and damaged more than 200 historical buildings. Flood disasters in these regions were mainly driven by the combined effects of climate change, topography, urbanization, and transboundary water resource conflicts. By systematically sorting out the characteristics and causes of disaster situations, it is helpful to summarize experiences and lessons learned, and provide useful references for the construction of flood control and disaster reduction system in China.