Climate change is considered as a distal determinant of public health which is increasing in importance. India, as an example, has a national action plan for climate change and human health. Sub-national (State) plans for climate change also exist, taking into account the health sector. The State of Bihar was selected for assessment because of its vulnerability (a function of exposure, sensitivity and adaptive capacity). A vulnerability framework was constructed by discussions with national and local-level specialists followed by weightage given by working in the field of climate and health with international exposure. A total of 15 districts were at a high risk of floods and these were considered for detailed analysis using the methodology for human development index as well as other examples in the field of environment. Climate health vulnerability index score were correlated with actual prevalence of flood mortality data of these 15 districts in year 2016. It was found that climate health vulnerability and flood mortality had negative low correlation of -0.25. In contrast for vector-borne diseases (VBD), both pre-flood and post-flood, the morbidity data had a correlation of 0.24 and 0.11 respectively. Possible reasons for a negative correlation for mortality could involve better preparedness by disaster district authorities. However, outbreak control is within the ambit of the health sector where a possible reason for decreased correlation coefficient in the post-flood period could be due to the impact on health facilities itself, thus leading to reduced reporting.