A weekly frequency of active commuting is associated with major health benefits. Recent evidence shows that there are fewer bicycle commuters during the winter season in North American urban regions. However, winter bicycle commuting is an increasingly popular practice in Quebec. If mode of transport choice is mainly driven by environmental factors (e.g., infrastructure, weather), systematic reviews support that the theory of planned behaviour (TPB) constructs and habit levels are associated with active commuting. To date, research has not yet determined the relation between those psychological constructs and winter bicycle commuting. To answer this question, this study aimed at assessing whether the TPB and habits constructs are longitudinally associated with winter bicycle commuting use among adults in the Quebec province. This longitudinal study was based on two online questionnaires. Significant positive correlations were found between intention-subjective norms (r = 0,13), intention-PBC (r = 0,60), intention-attitudes (r = 0,43), attitudes-subjective norms (r = 0,14), attitudes-PBC (r = 0,44), PBC-subjective norms (r = 0,17) and automaticity-intention (r = 0,12). The results also demonstrated that winter bicycle commuting was significantly predicted by both intentions, (? = 0.52) and automaticity (? = 1.14), meaning that the level of automaticity in winter bicycle commuting will be positively and longitudinally associated with the use of winter bicycle commuting. Altogether, this study helps to better understand those who winter cycle and why they choose to ride in winter. It also provides science-based data to be used by health promoters to enhance winter bicycle commuting participation.