This paper presents results of a longitudinal field study which aims to investigate adaptive comfort behaviours (i.e. turning on air-conditioner, turning on fans and opening windows or doors) in residential buildings. Field measurements were conducted in 43 homes in Tianjin, northern China, from Spring through early Winter in 2016. Occupants' ‘right-here-right-now' thermal perception and adaptive comfort behaviours were collected through online questionnaires delivered to their smartphones. Results indicated that clothing insulation adjustment was the requisite adaptive behaviour to attain thermal comfort. Clothing insulation was more climate-responsive in Tianjin's autumn than in summer. Statistical models were developed to predict the likelihood of various thermally adaptive behaviours with regard to outdoor air temperatures. An outdoor air temperature of 25.2°C was associated with maximum use of windows/doors for comfort ventilation and minimum use of air conditioning (AC). When outdoor air temperature exceeded 32.5°C, 50% of occupants turned on AC for cooling.