Have you ever had all your windows and external mirrors fog up suddenly while driving?

mb

Lifer
Jun 27, 2004
10,233
2
71
I was driving to work yesterday and out of no where all my windows fogged up, as well as my side mirrors. It was sort of surreal because there was no visible fog on the interstate, just some relatively low and fast moving dark clouds (but no rain).

Has anyone else had this happen to them? I asked several people at work, some of who have been driving for longer than I've been alive and none of them have ever heard of it before.

Luckily no one was around for the second I was blind until I realized what was going on and turned on my windshield wipers and the front and rear defrosters.

Oh, and this happened in the ML430, not the Accord. I took the ML b/c I am dog sitting and my boss is nice enough to let me bring him to work.
 

sniperruff

Lifer
Apr 17, 2002
11,644
2
0
external mirrors too? that's pretty weird. the inside of my windows will fog up if i turn off the heat when im driving...
 

FeuerFrei

Diamond Member
Mar 30, 2005
9,144
929
126
Inside or outside surface?

If it's outside maybe you drove through a wetlands area with high humidity and your chilled windshield fogged up.
 

mb

Lifer
Jun 27, 2004
10,233
2
71
It was the outside surface. I thought it was the inside at first, but realized it was outside as soon as I flipped on my windshield wipers. Also my inside rear view mirror did not fog up.

It was the same route I take to work everyday.. I don't know much about the land surrounding the interstate.. weather was relatively warm (50F or so) and I'm guessing it was very humid from the low, dark clouds and impending rain.
 

cprince

Senior member
May 8, 2007
963
0
0
It happened to me once, about two years ago. All of my windows were fogged up from the outside, but my two side mirrors were not. It happened very quickly. Luckily, I pulled over to the side of the road without incident. I think it could be hot steam from the sewer because I remember seeing some steam rising from the side of the road before I got fogged up.
 

warmodder

Senior member
Nov 1, 2007
553
0
0
Happens in my jeep alot. I'm not sure what causes it, and it takes a while with the defroster going full tilt to get it off.
 

Estrella

Senior member
Jan 29, 2006
900
0
76
Originally posted by: mb
I was driving to work yesterday and out of no where all my windows fogged up, as well as my side mirrors. It was sort of surreal because there was no visible fog on the interstate, just some relatively low and fast moving dark clouds (but no rain).

Has anyone else had this happen to them? I asked several people at work, some of who have been driving for longer than I've been alive and none of them have ever heard of it before.

Luckily no one was around for the second I was blind until I realized what was going on and turned on my windshield wipers and the front and rear defrosters.

Oh, and this happened in the ML430, not the Accord. I took the ML b/c I am dog sitting and my boss is nice enough to let me bring him to work.

You moved through a front, it happens sometimes when the conditions are right. It happened to me the other day.
 

Thump553

Lifer
Jun 2, 2000
12,824
2,613
136
It happens to me on a fairly regular basis. I live in a hilly section of New England, where we have our fair share of cool nights and the weather is frequently damp. It happens most often an hour or two after dawn when most of the air has started to warm and there is no wind. It tends to happen when I enter the shady side of a hill. My theory is I'm entering a region of colder, damp air with a warmer car. There are two spots near my home where this happens the most. At other times you will notice that this is where fog tends to develop first.

Put your defrost on high and the fogging clears up in fifteen seconds or so after you drive out of the cool region. Heated outside mirrors are great for this situation. It is startling (especially if you don't expect it) but is a relatively minor annoyance if you anticipate it.

A similar phenomena is probably the cause of those 50+ car pileups on the interstate you read about occassionally. One happened near to my home when I lived in the upper Midwest and from reading the articles about it, these accidents nearly always happen when there are banks of thick fog on otherwise clear days. Someone entering the fog panics, slams on their brakes and is rearended by someone else, starting the chain reaction. The thing to do in these situations is to let up on the gas and slow relatively gradually and stick to your lane (and pray).