From what I understand, long term certificates of deposit (CDs) typically offer higher interest rates than short term CDs. They do that to give you a reason to lock up your money for a longer period of time.
However, right now I see many financial institutions are offering CDs with APYs that go lower as the CD term gets longer. Here is an example from Fidelity:
Is there any reason to put your money in a longer term CD that pays less interest than a shorter term CD?