Squealing Noise during wet weather and temperature drop

HBomb

Having a hard time diagnosing the issue. This has occurred on and off for the past 3 years. As titled, it only occurs when the outdoor climate goes from warm to cool or vice versa, and typically when there;s high moisture in the air. Once outdoor temperatures stabilize, the issue fades away.

Noise is louder during idle and breaking, but less so at highway speeds.

Toyota dealership said it could be a water pump, idler pulley or some other belt, but won't diagnose the issue without $150. Otherwise, the vehicle is in excellent condition.

Thanks!