The paper investigates mobility options and practices of irregular migrant workers and international urban refugees during the 2011 flood in Bangkok, Thailand. Contributing to debates on disaster mobility and climate change induced displacement, the paper explores how citizenship and racialized differences unfolded during the flood event and how such differences had (de)mobilising effects for specific subgroups of Bangkok's irregular population. Drawing on the concepts of assemblage and affect the paper proposes to perceive of race as emergent within concrete interactions between bodies, rather than a pre-given social category or a purely discursive trope. From this perspective the body itself may become a repository to subvert or manipulate racialized perceptions. The paper argues that approaching race as an emerging assemblage helps to shed light both on the demobilising effects race had on people's mobility as well as on the fleeting moments of generosity and care between people that proliferated alongside such demobilisations.