Should You Wash Your Car When Rain Is in the Forecast?

Usually, yes. If there's anything on the paint that shouldn't sit there, such as bug splatter, bird droppings, tree sap or salt from a beach day, wash it no matter what the forecast says, because rain won't reliably take it off. If the car only has a light coat of dust and a downpour is about to start, waiting until it passes is perfectly reasonable.

The details matter more in Central Florida than in most places, because for roughly four and a half months of the year, rain is in the forecast most days.

Rain isn't a free car wash

Rainwater isn't pure by the time it reaches your hood. It falls through dust, pollen and air pollution, and the EPA notes that acidic compounds reach outdoor surfaces both in rain and in dry dust, where they make paint and metal on buildings and other structures deteriorate faster (EPA, Effects of Acid Rain). When the drops evaporate, whatever they carried stays behind as spots and film.

Then there's the road. Driving on wet pavement throws a mist of oily grime onto the lower doors, the rocker panels and the back of the vehicle. That's why a car often looks worse after a storm than it did before.

Rain also does little for the things that do the most harm when they linger. Owner's manuals make the same point. Toyota's owner's manual lists dead insects, bird droppings, tree sap and coastal driving among the reasons to wash a vehicle immediately, and Tesla's manual tells owners not to wait for the next full wash to remove them.

What "rain in the forecast" means in Orlando

According to National Weather Service records for Orlando, the wet season typically starts around May 27 and the dry season around October 15. Those are median dates, so any given year can run earlier or later.

During the wet season, showers and thunderstorms are a regular part of the day. If you waited for a rain-free forecast, you might not wash the car between Memorial Day and mid-October. A better approach is to plan around the pattern:

• Wash early. A morning wash gives you most of the day with a clean car and clear glass before the afternoon build-up.
• Or wash after the storm. An evening wash clears the fresh film before tomorrow's sun bakes it on. Washie is open daily from 6am to 9pm, so both ends of the day work.
• Don't chase perfection. In the wet season the goal isn't a spotless car seven days a week. It's keeping contaminants from sitting on the paint and keeping the glass clear.

From mid-October on, dry stretches get longer and a wash simply lasts longer. Dust and pollen take over from rain as the main things you're washing off.

When washing before rain makes sense

• Something harmful is on the paint. See above. The forecast doesn't change the advice.
• You want protection on before the storm. Water beading on clean paint is a sign the surface is protected; Toyota's manual uses exactly that test, advising owners to apply wax when water no longer beads. Rain that lands on a clean car also has less dirt to turn into streaks.
• Memberships are coming soon. Once Washie's unlimited car wash memberships launch, from $29.99 a month, washing again after a storm won't add to the bill; the wash packages page has the latest.
• You need a clean car today. A job interview, a client visit or a date doesn't care about tomorrow's weather.

When to wait

• The car only has light dust on it and heavy rain is about to start.
• A tropical storm or hurricane is approaching. Follow local emergency guidance and deal with the car afterward.
• There's lightning in the area. Waiting isn't optional then, and it deserves its own section.

Thunder means stop, especially in a self-service bay

Central Florida's storms bring serious lightning. The National Weather Service's guidance is to move to a substantial building or an enclosed, metal-topped vehicle with the windows up as soon as you hear thunder, and to stay there until 30 minutes after the last rumble (NWS lightning safety tips). NWS is also clear that open-sided shelters don't protect you.

A self-service bay has a roof, but it's an open structure, and you're standing on wet concrete holding a wand. If thunder starts while you're washing, stop and move into a substantial building or an enclosed, metal-topped vehicle with the windows closed. An open-top or soft-top vehicle is not the shelter described by NWS. The suds can wait.

After the storm

A quick wash once the weather clears removes the film and spots while they're still fresh, which is when they come off most easily. Pay attention to the glass, the lower panels and the rear of the vehicle, where road spray collects.

If you're in a self-service bay, make the spot-free rinse the last water that touches the car. Washie's posted instructions describe it as filtered water meant to prevent water spots as the car dries. Check and clean the wiper blades using the method and product in your owner's manual, and replace damaged blades.

FAQs

Next step: Washie is open every day from 6am to 9pm, so you can wash before the clouds build or after they clear. Check the location page for directions.