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Lines of frost inside windshield

Does anybody know if these frost lines are a concern? After seeing them several times I am convinced they are the same pattern. I was wondering if there’s some kind of coating that has cracked on The windshield.

If frost is forming on the inside of the windshield, that is an indication that there is excessive moisture in the air inside the cabin. That could be the result of a lot of snow falling off of the footwear of the driver and occupants, or it could be an indication that you have been running the heater on the recirculate setting (which you should NOT do!), or it could be an indicator of a leaking heater core.

Have you had a lot of snowy conditions in your area?
Have you been running the heater in “recirculate” mode?
Is there a somewhat “oily” film on the inside of the glass?
What is the model year of your Honda?


My first guess would be an oily film. When door glass breaks it seems to disintegrate into rock salt like pieces


I seem to recall seeing something like that on my truck’s windshield when I lived in Colorado. Not a common thing, required a certain sort of weather conditions. One idea, next time you see this make a mark (one that can be easily removed obviously) where one of those lines is located. The when the windshield has been defrosted and dried out, use a loupe to carefully look for anything unusal on the glass surface. I’m thinking it’s related to the dirt pattern on the glass.

You suggest a scientific research approach, George :slight_smile:
I thought of the dirt too, but my advise would be to CLEAN THE DAMN GLASS :slight_smile:

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My first impulse was to suggest cleaning the glass inside and out. Not sure if this frost is on the inside or outside of the glass also.

If its inside…it looks like the frost is avoiding where Billy used his Crayolas drawing Mommy a picture on the inside of the glass… ?

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We used to blame that on Jack Frost creating his designs. When I have the weekly drive of four blocks from a moist garage to sit outside for an hour or so, I always have frost on the inside of the windows if it is cold enough, Usually have to sit there for a few minutes to clear the windows enough to drive. Sometimes if I park toward the rising sun, I don’t have as big a problem. But yeah, if it happens once, there is residue after that on the window so that it needs to be cleaned again. Winter is a challenge.

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The lines appear to absent of frost, likely from a film on the glass from using a soft piece of plastic to scrape the frost from the glass. Clean the windshield.

The frost is from excessive moisture and poor ventilation. Dry out the carpeting.