I Don’t Understand What Caused This to Happen in My Car Overnight

We're currently in the midst of some crazy weather patterns here in Maine with big temperature swings forecast over the span of 12 hours and heavy rain with up to a foot of snow days apart. So at this point, nothing surprises me with the weather, except for this that I have never seen before.

I got into my car Wednesday morning after a soaking rain overnight. The temperature was 54 according to my dashboard, but I could barely see the speedometer and tachometer displays becuase they looked like this.

That picture is not blurred. That's condensation on the outside plastic over the dashboard displays. I have two another LED displays on the dash that were not affected.

My first thought is that I must have had a window cracked, but I couldn't remember putting any windows down recently since it's been so cold. I checked all four by pressing the up buttons that control each of them and none of them moved, so they seemed to be sealed shut.

I was also concerned that the condesation was on the inside of the display, but I touched it with the tip of my finger and it was clearly on the outside.

So I of course turned to a Google search for an answer and according to NAPA, there are three possible causes. Wet floor mats or carpets might have water sitting in them,  cups with liquid in the them such as water of coffee. NAPA says the worst case scenario is that your heater core is leaking warm coolant that can make their way into the cabin, creating condensation.

Looking down and my floor mat, it's kind of a mess so I'm guessing that might be the culprit. At least I sure hope so. That heater core thing doesn't sound like a cheap fix.