Humanitarian actors expect operations to be seriously impacted during the rainy season in Cox’s Bazar. This will result in interruptions in humanitarian operations including life-saving services such as ambulances and on-going aid such as food distribution. This brief outlines the potential impact of rains, floods and landslides in the camps of Cox’s Bazar. To do so, it draws on past impact of rains in these camps, as well as in Cox’s Bazar and in Bangladesh more generally. It also draws on similar camp settings and natural disasters in other countries. Wherever possible, it is grounded in informal discussions with experts in their sector, meeting notes and field observations. The camps at this scale have never existed in this season before, so there is no direct past experience of how they have withstood a monsoon. Key priorities are: Highly unsanitary conditions (Damage to latrines and structures, contamination of water sources), Waterborne diseases, and Damage to shelters (resulting in exposure to the elements, displacement and overcrowding).