Thermal adaptation in low-income housing of Mumbai, India is investigated using a longitudinal field study and in-situ field measurements. 705 set of responses from two different neighbourhoods were analysed to understand the patterns of behavioural adaptation. Spatial configuration, temporal factors and underlying societal norms influenced the comfort-related behaviour in low-income housing. Clothing adaptation was primarily governed by the gendered socio-cultural practice of purdah system and western influences rather than thermal needs. Logistic regression predicts probabilities of 88% and 20% for using ceiling fans and exhaust fans respectively at 80% indoor air relative humidity. However, thermal stimuli cannot predict occupant behaviour well due to presence of non-thermal determinants. Security, privacy, environmental nuisances (dust, noise and odour) and insects or animals menace (mosquitoes, monkeys, rats, lizards) were the major barriers to thermal adaptation. The study is helpful in evaluating the influence of occupant behaviour on building performance and thus to inform building design and operation. The policy implications could be through the development of design guidelines for the housing schemes to create thermally comfortable low-income dwellings.