Governments are seeking to slow the spread of COVID-19 by implementing measures that encourage, or mandate, changes in people’s behaviour such as the wearing of face masks. The success of these measures depends on the willingness of individuals to change their behaviour and their commitment and capacity to translate that intention into actions. Understanding and predicting both the willingness of individuals to change their behaviour and their enthusiasm to act on that willingness are needed to assess the likely effectiveness of these measures in slowing the spread of the virus. We analysed responses to two different regional surveys about people’s intentions and behaviour with respect to preventing the spread of COVID-19 in New Zealand. While motivations and intentions were largely similar across the regions, there were surprisingly large differences across the regions regarding the frequency of wearing face masks. These regional differences were not associated with regional differences in demographics (or in Alert levels) but were associated with regional differences in the number of confirmed cases of COVID-19. The results highlight the importance to policy design of distinguishing the factors that might influence the formation of behavioural intentions from those that might influence the implementation of those intentions.