What Causes Car Brake Pads to Squeak on Rainy Days?

[DelLiam]

When the car brakes squeak, the following are the reasons why it worsens on rainy days: 1. Fine sand adheres to the brake disc: Rainwater carries fine sand that sticks to the brake disc. In humid weather or when there is a large temperature difference between day and night, dew or rain can cause the brake disc to rust, which acts like tiny particles. Car brake pads come in hard and soft varieties. Hard pads are more wear-resistant, but if there are tiny particles between the hard pads and the gray cast iron brake disc, they can produce a sharp squeaking sound. A few brake applications will wear off these small particles and the noise will stop. 2. Break-in period: The break-in of a new car includes an important phase for the brake pads. Typically, after driving a few hundred kilometers, the braking will feel more comfortable. Newly replaced brake pads also need a break-in period to better integrate with the old disc. Initially, the brakes may feel very stiff, and it usually takes a few hundred kilometers of driving before they feel better. 3. Missing brake disc fixing screws: Missing or damaged fixing screws on the brake disc can also cause brake noise.

[LeClayton]

The squeaking sound of car brake pads on rainy days is mainly due to issues with the brake surfaces. Rainwater can wet the brake discs and pads, causing surface rust or dirt buildup, which creates a squeaking noise during friction, much like a rusty lock. With over a decade of driving experience, I’ve encountered this situation many times. Once after heavy rain, the braking sound was particularly sharp, startling me into slowing down immediately. Upon inspection, I found significant rust buildup on the discs—turns out, brake components are prone to oxidation in damp conditions. The solution is simple: if the noise disappears after the weather improves, there’s no need to worry. However, persistent unusual sounds warrant a visit to the repair shop for resurfacing or replacing the brake pads. Driving at lower speeds in the rain can also reduce noise. Making it a habit to clean dust around the wheel area during regular maintenance helps prevent excessive debris buildup, which can worsen the issue. Above all, prioritize safety—never ignore these small warning signs.

[SanJeremiah]

Brake pads making noise on rainy days is mainly attributed to moisture affecting the friction surface. When brake discs get damp, rust or contaminants easily form on the surface, causing squeaking sounds during braking. Having driven different car models, I've noticed material differences also play a significant role—cheaper brake pads tend to absorb water and deform more easily. Rain acts as a trigger, especially when the car is parked outdoors for extended periods, allowing moisture to accumulate faster around the wheel base. In daily driving, if you encounter this issue, don't panic—lightly applying the brakes to generate friction heat helps evaporate the moisture and often resolves the noise. However, if the noise persists, it may indicate pad wear or material aging, requiring professional diagnosis. Switching to rust-resistant brake pads has proven effective, and I've recommended this to friends with positive feedback. Maintenance awareness is crucial—driving cautiously in rainy conditions is always wise.

[DeJuliet]

Brake squeaking in rainy weather is common due to moisture causing surface roughness and friction. Rust or dust on the discs can also lead to creaking sounds under contact pressure. I've experienced this, and the solution is straightforward and effective. After rain, lightly apply the brakes a few times while driving to expel water and debris, which often restores quiet operation. If the noise persists, it may indicate the need to inspect for worn components. Regular cleaning of the wheel area can prevent water and grime buildup. Simple maintenance usually suffices—don't let the noise affect your driving mood.