6 Simple Reasons Why Cars Get Dirty When It Rains

You probably think rain washes your car.

Of course, the natural thing is that water cleanses dirt stuff, so you shouldn’t expect to see dirt on your car after a heavy downpour.

However, the reverse is the case when it rains on your car.

Quick Answer

As a general rule, cars get dirty when raining because rain isn’t completely clean but contains dirt, acid, and other contaminants that can leave your car dirty after a downpour. 

No matter how heavy it rains, it doesn’t wash cars clean; instead, it can leave dirt on your vehicle and the car in worse condition.

Therefore, you better think again if you feel you needn’t wash your car after it rains.

Rain can do more damage to your vehicle than wash it, as you feel. 

Find out why cars remain dirty after rain.

Do Cars Get Dirty When Raining?

You may think you can get away with not washing your car if you live in rainy climates or during the rainy season.

Contrary to what you believe, rain doesn’t wash your car, as you think.

While you may choose not to wash your car after raining, you’ll see that it isn’t in your best interest. 

As a whole, cars can get dirty when raining due to the following reasons:

  • Rainwater contains impurities
  • Rain causes tree sap on the car
  • Attracts dirt
  • Leaves water spots
  • Rain is acidic
  • Has low pressure

Don’t be surprised when your car is dirtier after rain.

It’ll hurt even more if it rains on your vehicle just when you finish washing it because you might need to rewash it.

Rain will not only make your car dirty, but it can also be bad for the paint. 

Here are the reasons for that:

Rainwater Contains Impurities

Rainwater isn’t as clean as you think.

It might come directly from the sky; however, it gets contaminated before contacting your car. 

When it reaches the atmosphere, it sucks the dust in the atmosphere and dumps it on your car.

Sometimes, you may notice these impurities on your car after the rain.

Either way, you should wash your car after it rains.

Rain Causes Tree Sap On The Car

Tree saps are some of the most damaging contaminants you can get on your car, and sometimes, they can be difficult to remove.

Tree saps gather on trees, and they can get on your car when leaves fall on your vehicle. 

If you ignore your car after rain, the sap will bond to your car’s finish and be hard to remove.

Therefore, your car will be dirty after the rain.

Attracts Dirt

You shouldn’t trust the rain to keep your car clean. Rain easily attracts dirt to your car.

For example, as the rain touches the ground, it splashes dirt and debris on the body, which even worsens if you drive through a puddle. 

Furthermore, the soaked car body makes it easy for dirt and debris to cling easily to the car.

This will leave obvious dirt on your car, and you will need to wash your car.

Leaves Water Spots

Rain can leave water spots on your car, which isn’t a great look on your vehicle.

The impurities in rainwater leave a chalky residue on the car when the water evaporates.

These chalky residues may seem harmless, but they’re slow poisons that eat into your car’s paint.

The chemical and impurities in the water will corrode the paint if you leave it on your car for long or at high temperatures, causing etching that eventually damages the paint. 

Rain Is Acidic

Pollution from different sources gets into the air and contaminates rainwater, making it acidic.

Acid isn’t great for your car and can ruin the paint. 

If you wash your vehicle after a downpour, you may prevent that, but if you leave the acidic rain on your car for a long time, eventually, you will have to redo your car’s paint and protection. 

Has Low Pressure

You shouldn’t expect rain to wash your car because it has low pressure.

If, for a moment, you forget the impurities or acid that may contaminate rain, you still wouldn’t get a clean car.

Rain has low pressure and won’t wash off any dirt or debris on your car, and instead will make it worse.


Rain does more harm than good on your car.

Instead of washing your car, it’ll get more dirt and contaminant on your vehicle and damage the paint.

Therefore, ensure you wash your car with a car wash shampoo and dry it using a microfiber cloth after it rains. 

Key Takeaways:

  • Rainwater contains impurities that contaminate cars,
  • Acid from rain will ruin the car’s paint,
  • Rain leaves water spots on cars,
  • Wash your car after it rains to prevent any damage.







Jan-Lucas Ganssauge
Jan-Lucas Ganssauge