Local governments are expected now more than ever to lead climate action planning as climate change intensifies and urbanization increases rapidly. However, studies indicate limitations in the comprehensiveness and level of integration of adaptation and mitigation in existing climate action plans. To develop suitable climate action plans that are comprehensive and consistent with globally accepted standards and benchmarks, this study proposed an Urban Climate Action Planning framework and pilot-tested it with 257 urban climate action plans. Overall, 43 criteria are included in the framework across three stages of climate planning. The pilot test revealed that more than half of the sampled plans have a medium level of suitability, with 39% having a weak level of suitability. About 51% of plans from Europe have a weak level of suitability. Surprisingly, none of the plans sampled from Africa and Latin America achieved a weak level of suitability despite lacking a significant share of global climate research and development funding. A Kruskal-Wallis test shows a statistically significant association between stages of climate planning and (a) city types (p-value of 0.004326) and (b) year of adoption or publication of climate plans and suitability scores (p-value of 0.0001027). Urban climate action plans adopted or published more recently (2018–2022) are likely more suitable than those adopted or published earlier. The sampled urban climate action plans from the Global South had higher average suitability scores than those from the Global North. The study presents key findings and considerations for urban climate action planning and future research.