If planning is to matter for urban development and policy, it is not sufficient for plans to be implemented. Plans and planning must also have a causal role—they must lead to outcomes that would not be realized otherwise. In case studies of municipal climate action planning in California, I find little evidence for any causal impacts. Instead, cities are using climate plans to codify policies that were likely to happen anyway. The results call for a more nuanced view of when it makes sense to plan, what types of plans are most useful, and how to evaluate a plan’s effects.