Cities must play a leading role in addressing climate change impacts as they concentrate important assets and vulnerable communities. As urbanization increases, cities will be highly impacted by climate extremes that infrastructure and plans have not accounted for. To avoid potential losses and damages, cities need to take action as quickly as possible by securing funding from governmental, bank, private sector, and other sources to implement adaptation measures. A lack of action risks exacerbating impacts due to poor governance and lack of political commitment, knowledge, and funding allocated to reactive approaches rather than proactive adaptation. The Covenant of Mayors for Energy and Climate can help guide city climate action.