When broken AC can (rarely) justify leaving
Rarely on its own. Because AC is usually not a required habitability item, broken AC alone typically does not justify breaking a lease. It can become a stronger reason if AC was promised in your lease, or if extreme heat makes the home genuinely unlivable — but doing it wrong can leave you owing rent.
Moving out under "constructive eviction" requires conditions serious enough to make a home unlivable, plus notice to the landlord and a fair chance to fix them. A warm apartment usually does not meet that bar by itself, while dangerous heat combined with a lease that promised cooling might.
Because the risk of owing the remaining rent is real, this is a decision to run past an attorney first. Before you move out over broken AC — or sign anything the landlord offers — a free, confidential review can help you avoid a costly mistake.
This is general information about California tenant rights, not legal advice. Every situation is different.