Is It Better to Wash Your Car in the Sun or Shade?

Taking care of your car is an essential part of vehicle ownership. One of car owners’ most common questions is whether washing their vehicle in the sun or shade is best. While it may seem simple, the answer is more complicated than you think. But in short, washing your car in direct sunlight can damage the paint. In this article, I’ll explain why washing your car in direct sunlight can be a mistake and provide tips for washing your car in the sun to avoid damaging your vehicle’s finish.

Why Shouldn’t You Wash Your Car in Direct Sunlight?

Washing your car in direct sunlight can damage the exterior of your vehicle. The heat can cause your paint to dry out between washes and leave water marks on the bodywork. It can also reduce the effectiveness of cleaning products. Here’s why you should avoid washing your car in direct sunlight.

Water Spots And Streaks 

In addition to being unattractive, water spots can etch your clear coat or leave spider-webbing scratches on your paint.

Washing your car in direct sunlight is a very common mistake. It is not only bad for the finish of your vehicle, but it can also make detailing your car more difficult. The sun’s heat dries water faster than usual, which makes water spots more likely.

Damages the paint

Paints are UV-absorbing and need special care to prevent UV-induced damage to the objects they cover. For example, a painting with a high proportion of pigments may require extra protection from sunlight. This is no different to your cars paint.

The sun’s ultraviolet rays can damage paint by speeding up oxidation. This UV light causes a reaction between the surface and the light, causing molecular bonds to break. This will result in streaks and other damage to the paint.

Tarnishes the finish

When using cleaning chemicals, if left to dry out or burn into the paint from the UV rays, it can cause a reaction with the clearcoat (protection layer on top of the paint), destroying the finish.  

Tips for Washing Your Car in Direct Sunlight

When washing your car in the sun, keeping the process as short and easy as possible is a good idea. First, make sure to have all of the cleaning products you’ll need throughout the whole clean ready. When washing the car in direct sunlight, the vehicle from the top downwards and try to keep each panel wet and prevent it from drying out too quickly. Here are some more tips below to help you prevent damage. 

Wash the car quicker to stop the vehicle from drying in the sun

You want to avoid drying the car in direct sunlight, so wash the car faster. Start by wetting the vehicle from the top down, preventing the drying process from taking too long. When finished, dry it with a microfiber towel starting from the top to avoid; using a microfiber drying towel will stop you from scratching the paint and stop the sun from burning the water into the paint.

One last tip is to start on the shaded parts of the vehicle. When you rinse the soap from the door, you should rinse the fender and the door next to it. This will mean you are washing the side of the car in the sun last, then dry the sunnier side first. 

Keep each panel wet

Stop the sun from drying each panel by applying more water. During the washing stage of cleaning your car, have your pressure washer or water hose on standby to apply more water to panels that are starting to dry out. 

Wash each panel separately

When you’re washing your car in direct sunlight, your strategy for cleaning it needs to change. You have to work in smaller sections to apply soap more quickly. It would help if you washed each panel separately, starting from the top and working down to the lower sides. The dirtiest part of your car is the bottom third, and dirt is kicked up onto the paint by this area, so you always start at the top.

Regardless of the weather, start cleaning by washing the wheels, engine bay, door jambs, plastic trims, and other exterior elements first. Once these areas are cleaned, rinse away any soap and dry with microfibers. 

Use uv safe products

When washing your car in direct sunlight, using UV-safe products on the vehicle and yourself is important. Always remember to apply sun lotion when working in direct sunlight. Using UV-safe products on your car can help prevent damage caused by the sun’s rays. You can use spray wax or drying aids to avoid water spots or damaging marks appearing in the paint. These products contain ingredients that benefit the health of your car’s paintwork.

Avoid waxing the car

When waxing your car, it’s essential to be careful, especially if you’re doing it in the sun. UV rays can have a negative effect on the wax, which can, in turn, damage your car’s paint. To avoid this, it’s best to choose a cool day below 80 degrees Fahrenheit (27 degrees Celsius) or apply the wax in the shade. This will ensure that your car’s paint stays protected and you get the best results from your wax job.

Best Weather to Wash Your Car

The ideal weather to wash your car is when the temperature is between 32 degrees Fahrenheit (0 degrees Celsius) and 80 degrees Fahrenheit (27 degrees Celsius). This is because, in freezing temperatures, the water on your car can harden and cause a crack in the windshield. However, this doesn’t mean you should avoid washing your car in colder weather altogether. 

On the other hand, hot weather can also damage your car’s finish. While it may help clean off dirt, the water quickly dries up due to the heat. This can cause the hot metal to steam off the soapy water, leaving behind remaining moisture that attracts heat from the sun. This can damage new paint jobs and the thin topcoat on new cars.

Frequently Asked Questions

Does Sun Damage Car Paint?

Yes, the sun’s UV rays can damage car paint, causing fading, chalking, and cracking. To protect your car, park in shaded areas, use a car cover and wash and wax it regularly.

How Do You Prevent Water Spots When Washing Your Car In The Sun?

One way to prevent water spots when washing your car in the sun is to wash your car in sections and dry each section immediately after washing it. This will stop the water from drying on the car’s surface and leaving behind water spots. Another way is to use a water softener or a water spot remover solution to neutralize the minerals in the water. 

Final Points

While there are certain benefits to washing your car in the sun, you also want to avoid streaks and water spots. The hotter the surface is, the faster the soap will dry, leaving unsightly marks and streaks. The opposite is true when you wash your car in the shade.

The ideal time for washing your car is before the sun heats up. Doing this morning or night when the air is cooler is be best. In the summer, the sun can cause soap to dry before you can rinse it away. If you must wash your car in the sun, consider each tip highlighted in this article. This will ensure you minimize the risk of damaging your car paint.

My name is Tom although my friends call me Tommy. Messing around with cars and bikes has always been a hobby of mine even from a young age. So I made it my day job 17 years ago. I am a fully qualified mechanic as you would expect. I've worked in all different areas of the motor trade, valeting, panel beating, engine repairs, I'm sure you get the idea. I enjoy sharing my wealth of knowledge and experience with others, which is the reason I spend a lot of time here writing for this website.

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