How about the air intake being full of partially composted leaf mould, and thus the pollen filter gets soaking wet in the rain......

Hi,

I had this same issue and after much research found the issue and solution. 
 

it seems the windscreen wasn’t bonded properly in the factory and the top inside of the screen should have been ‘roughed up’ to enable the screen sealant to bond. See pics .. the metal strip across the top is the issue. 
 

If you push the top inside of your windscreen you’ll see it move. It’s not bonded and the screen needs to be taken out and put back in. 
 

I did this at a cost of @ £150… you’ll then need to replace the sodden pollen/cabin filter and it’ll also take a few weeks/months for the sound insulation under the screen to dry out fully. 
 

I have a water catcher I placed in the boot that helped to speed things up drying wise. 
 

I’ll try to add some pics of mine when I did it late last year. 
 

Hope that helps. 

Guys, I'm having a similar problem with a little water dripping near the light and sunglasses holder in my 2012 Focus MK3 (without a sunroof). My windshield is also wet on the inside in the morning. The car floor is dry (both driver's and passenger's side) and sometimes it even drips in the area of the sunglass holder. I recently fixed the problem of water getting in through the trunk. Does anyone know what it could be? 

I live in Portugal (wheather on winter arrownd  2-5 degrees) and I park on the street so the issue could be only condensation as mentioned buy the folks here or could also be some leak in the front ?

My AC I think its ok, I've regas it less  them one year ago