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Washing Your Car in Rainy Weather? 5 Reasons Its Pointless

You want to keep your car looking great…but those rainy days can make it difficult. Rain water isn’t nature’s free car wash assistant (even though a lot of people seem to think it is).

Simply put: if the weather forecast calls for rain, it’s simply a waste of time and money to wash your car or use any type of car wash service.

In this blog, I’ll break down a few main reasons why it’s best to wait until the next sunny day to wash your vehicle.

1. Rain water can be dirty water

Even if you’re thinking about washing your vehicle in light rain…it’s best to hold off since rain water isn’t always clean water. Sometimes rain can mix with pollen, pollution, and other airborne contaminants you don’t want on your vehicle.

According to the World Health Organization, 95% of rainwater is too polluted to drink without treatment. While this isn’t the case everywhere, it’s worth noting if you live in an area with heavy smog or pollution.

In rare cases, acid rain containing sulfuric or nitric acid can leave water marks or water spots you’ll need to remove later on.

2. Increased chance of water spots

Even if you live in an area with relatively clean rainwater, you still may notice water spots if your car dries due to evaporation.

You increase the risk of water spots on your vehicle’s paint if you can’t dry your vehicle properly. When the hot sun returns after a rain shower, water beads dry fast; when you control the drying process, it’s easier to remove water beads the right way using a microfiber drying towel or air dryer.

Quick Tip

At a minimum, apply a basic paint protection product like a sealant or wax to prevent water spots from forming your car’s finish. For best results, apply a ceramic coating with extreme hydrophobic or self-cleaning properties.

3. You can’t add protection to the clear coat of your car

To get that clean vehicle you want…it isn’t just about removing loose dirt–you need to add a protective layer. At the end of the way, if you wash your vehicle in the rain is that you won’t be able to apply wax, sealants, or other paint protection products until later.

As a best practice, always add wax or add protection immediately after washing and drying (if you can’t work in a garage). Floating debris or splashing water can ruin a decent car washing job if you wash in the rain but protect your car’s surface at a later time.

4. Wet roads are filled with dirty water

Even if your car looks a bit cleaner after taking it through a car wash in the rain…chances are it will get dirty again on the ride home with either muddy water or grime.

When rain water mixes with oil, brake dust, grease, and everything else on the road, this road grime can easily splash onto your car’s paint. Road grime turns into what is referred to as traffic film when dry; this thin film layer is more noticeable on light-colored vehicles and can’t be removed with water and soap alone. To remove traffic film, you’ll sometimes have to use a wax-stripping degreaser which isn’t ideal.

If you can help it, wait until the roads are completely dry before you drive your vehicle to keep it clean.

5. Washing in heavy rain can be dangerous

Water, sheet metal from your car, and electricity don’t mix. No matter if you’re in a heavy downpour or a light rain, you should stop washing immediately to avoid electric shock caused by lightning.

There’s typically metal on the bucket handle, on the hose nozzle, on the pressure washer lance…you get the idea.

Protect your vehicle against dirty rainwater

Even if it’s rainy season where you live, your vehicle will look a lot better once the rain dries if you have a plan to keep it protected.

As long as you keep your vehicle protected at all times, you can largely avoid the negative effects of rain water. At the end of the day, a clean car is typically a protected car.

To learn how to wash your car like a pro, check out our video course Washing and Detailing for Beginners. We’ve compiled over 2-hours of helpful content to help you get the sparking-clean results you want the next time you wash…without breaking the bank.

Ready to improve your washing and detailing skills?

This video course unpacks the fundamentals of washing and detailing. From exterior cleaning and blemish removal…you’ll learn the secrets that will give you spotless pro-level results!

Baxter Overman is the founder of Carwash Country and has been been cleaning up dirty vehicles for nearly 20 years. Since 2017, he's helped thousands of beginners see better results by learning the fundamentals of washing and detailing. He's on a mission to make the car wash process more fun...and way easier.

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