This paper investigates how board members’ unexpected flood experiences affect their firm’s Environmental, Social, and Governance (ESG) performance. Using anonymized individual-level travel data from China during 2017–2022, we identify flood experiences of publicly listed companies’ boards. Employing a staggered Difference-in-Differences method, we show that the firm’s ESG rating increases by 2.3% (4.03%) eight quarters after the board’s flood experiences during business (personal) trips. The effect is more pronounced when the flood is extremely severe and when the affected board member holds a higher ownership stake. We rule out alternative explanations such as disaster relief efforts. In addition, we provide evidence on the value mechanism behind the ESG improvements after flood experiences by showing that the ESG improvements are correlated with the costs and benefits of ESG improvements and the business exposure to flood risks. We also provide evidence on values mechanisms by showing that the ESG improvements are correlated with inherent personal characteristics such as gender.