Assessment of climate change mitigation policies in 315 cities in the Covenant of Mayors initiative

•More than 12 000 policies reported in 315 MEIs of signatories to the CoM have been assessed.•An aggregation process for harmonizing the policies submitted in the MEIs has been conducted.•Policies have been classified according to two policy criteria and correlated with the grouping of signatories according to contextual drivers.•The methodology provided in the study can be further used to assess potential differences with submitted SEAPs.