Frost on the inside

When I got into my car last night to go home I had frost on the inside of my front window. I have never had that happen before and even when it has been colder. What can cause frost to build up on the inside of a car window if all the windows are closed and such?

Humidity levels

Air moisture content…aka humidity.

My 06 Escape hybrid had that same problem.
The moisture is introduced by the occupants. In this weather it’s the shoes with snow residue transfered to the mats. Then you lock in the humidity with windows closed and temperature inversions , you get interior frost.

– When parked do NOT have the heater in recirculating mode, Let the interior breathe in the regular or vent mode.
– Get a box of school chalk and put several sticks here and there around the interior. They absorb humidity well. I put one in each door pocket and a couple under the seats. you can also use the silica gel packs that come in products you buy.
– On a day that you know your shoes had lots of snow on them, park with a window down just a tad.
– Remove mats and allow to dry fully once in a while during this season.
– If able to plan ahead, have a window down and the heater on high to expel as mush as posible prior to parking.

These measures solved my problem.

Got Escape new in 06, had interior frost winter 06 and 07. None since then.

When it happens (see instructions from ken to help prevent it happening) make sure the heater is on high and the recirculate is not on.  You want fresh (cold dry) air.