Brake squeals on hills and non-level surfaces

I know brake squealing indicates worn brakes and time to check/replace. But I notice on my 2009 Hyundai Accent, the squeal only happens going downhill (maybe uphill too, but one usually doesn’t brake much there), and on non-level surfaces at times. But for most day to day driving it’s level enough to not hear any squeals.

My question is what might this indicate with regards to the brakes or other components? Is it a special type of wear or uneven wear of the brakes? Since even wear would have the brakes squealing all the time I’d assume.

I’m going to have it inspected, but wanted to get some thoughts here beforehand.

Brake wear indicators squeal to let you know that the pads are worn. The calipers can stick if the pins are not lubricated and this will cause the brakes to wear more on one side vs the other. I would just have them checked at a local mechanic before your problem gets expensive.

Brake squeals may indicate nothing is wrong. Some brakes squeal a little bit from time to time. The wear indicators are a very annoying squeal, on purpose, to get you to check the brakes. Do that, as @knfenimore suggests. If the brakes pads don’t need replacing, the mechanic can add a little bit of anti-squeal grease to the pads to quiet them down.