Windshield exterior gets foggy in the rain

I’ve been driving a 1999 Toyota Camry LE for a few years now, and in the past few months I’ve started having a major problem with the exterior of the windshield fogging up in rainy weather. When the wiper blades move across the windshield, I get what appears to be a bit of fog across the entire wiped area, and it clears after a second before reappearing again when the wipers move. When I’m driving on an undivided highway at night with other cars coming towards me, this effectively reduces my visibility to about 40% while I wait for that fog to lift.

I just bought new blades in September, so I wonder if they might be the problem. Are my new blades just leaving a thin film of water on the windshield that has to evaporate? Or is there another problem that requires more than simply buy new blades?

The blades might be the problem.

Did you drive through the car wash and let them apply the spray wax?

Have you applied “rain-X” or a similar product?

Using the defroster with the AC in warm humid weather can also cause repeated fogging. The glass can get cold and the warm, saturated outside air deposits condensation on the surface of the glass. It can happen instantly each time, as soon as the wiper passes by. Mine will do this occasionally.

Road oil, pitted windshield, imported wiper blades that “bleed” plasticizers…

I Get That Whenever I Use “Rain-X” Washer Juice. The Same Thing happens When I Apply Rain-X Windshield Treatment. I Think I Am Now Using Prestone -34F DeIcer Fluid For Winter.

Takes A While To Wear Off The Rain-X. Try different juice or blades and give it a while. You might try cleaning the windshield and blades with denatured alcohol to see if there’s any immediate results, eh?


You have some kind(s) of residue on the windshield, and this is exacerbated by the typically worn, pitted windshield that most 10 year old cars would have.

I would suggest using isopropyl alcohol as a solvent to remove the (pick one or more):
Car wash spray wax
Motor oil
Industrial crud

You may have to use alcohol more than once to remove everything. Use the alcohol generously, but be careful not to get it on the paint. Use lots of paper towels, changing them frequently. And, don’t forget to clean off the wiper blades, which are also coated with whatever is gunking up your windshield.