The study looked at how different types of El Niño events affect the rainy season in the Huaihe River basin. They found that the onset and retreat of the rainy season moved northwards and westwards, with more rain in the south. Rainfall was strongly linked to sea surface temperatures in certain regions. During certain El Niño events, the basin experienced dry spells, while others brought more rain. The monsoon and atmospheric circulation played a big role in these patterns. Overall, stronger monsoons and anticyclonic flows led to more rain during the rainy season. These findings can help predict the rainy season and rainfall patterns in the Huaihe River basin.