With climate change, the frequency and intensity of certain climate hazards will increase, leading to greater impacts on the health of urban populations. Although cities can adopt various climate change adaptation (CCA) measures (e.g. urban/land-use planning against the effects of urban heat islands), little is known about the progress made in this regard, because of a lack of valid CCA measurement and evaluation tools, as well as organizational factors leading some cities to action and others to inaction. This study aims to create valid CCA indices, measure adaptation levels, and identify the main predictors at the municipal level. Four surveys were administered in 2016 to four groups of municipal officials: general managers, urban and land-use planners, public works managers, and emergency and civil protection officers, in the cities in Québec (Canada). Based on the theory of planned behaviour (Ajzen, 2005) and the Health Belief Model (Rosenstock, 1974), we measured the frequency of adoption of behaviours to prepare for heat waves and flooding, as well as some of their potential determinants (e.g. behavioural intentions, perceives severity of damage). Results of item analyses and confirmatory factor analyses provided support for the validity of four CCA indices designed to assess the level of climate preparedness of the municipalities. Results of path analyses indicated that the severity of potential damage to the municipality, the behavioural beliefs concerning the adoption of CCA behaviours, and the control beliefs by municipal officials were the main predictors of CCA. The validated indices enabled a first measurement of how prepared Quebec municipalities are to face climate hazards, leading to a monitoring over time of the progress made, which will help guide urban planning decisions. By identifying the attitudes, beliefs and skills to be strengthened, the results will help to develop training content for municipal staff to strengthen adaptation practices.