It's pretty obvious that landlords are required to provide the basics: locking doors, hot water, and heating.
But one of the questions that gets asked the most in landlord-tenant law is whether a landlord is required to provide tenants with air conditioning.
The answer? Probably not.
Every state, and most municipalities, have requirements that a landlord must meet while someone occupies a rental unit. These are generally known as a landlord's warranty of habitability, and are meant to ensure that tenants have access to basic necessities.
While heating is always required of a landlord, air conditioning is generally not. If it is required, it's likely that you'll find a provision in local rental law as opposed to state law, but be sure to check both.
Now, what if you already have air conditioning and it's not working properly?
A landlord's failure to properly maintain an air conditioner that he has already provided is not a matter of rental law, it's a matter of contract law.
Generally speaking, the rule is that if your landlord has provided you with an appliance, he is contractually obligated to provide one for the duration of your lease. He must also maintain and keep it in working order.
In other words, if the unit was placed in your apartment by your landlord, air conditioning must be maintained until you move out. A failure to do so would likely put your landlord in breach of contract, allowing you to potentially reduce your rent or move elsewhere.