The most common version: you hit the button and nothing happens, or the door gets a few inches up and stalls. That's almost always a torsion spring that's lost its tension or broken outright - one side carrying the full weight of the door instead of splitting it with the opener.
A second pattern is the loud bang from the garage, usually first thing on a cold morning, followed by a door that won't budge at all. That's the spring snapping under the stress of the overnight temperature drop, which lines up with the climate pattern here more than with anything mechanical going wrong inside the house.
Third: the door runs but sounds wrong - grinding, slow travel, or reversing partway through the cycle. That's usually the opener itself, and on a unit that's original to a house from the 1980s or 90s, it's often cheaper to replace the opener than keep repairing a motor built to a different duty cycle than what's sold today.