'97 Corolla moisture issue?

I have a '97 Corolla with 198K miles… this week all of a sudden, it has a strange moisture issue. It rained some on Sunday and a little Monday morning. I got in the car to go to work, and there was fog on the inside of the instrument panel window–turning on the defroster fixed it, but that’s the first time I’ve ever had to defrost my speedometer!
Monday while I was at work, it rained a lot more. I got in the car to go home, and it was very humid inside! I turned on the air and opened the windows for a minute, and all was fine.
It hasn’t rained since, but due to the moisture now the car smells pretty bad at first in the morning…I have to turn air on/open windows for a minute when I get in.
What would allow moisture to get inside the instrument panel??

First thing, check the setting on your fresh air switch. Make sure it is not set to Recirculate.

You’re leaking in one or more places. This would not be odd at all for a car this old. The whole area around the windshield, especially at the bottom is one likely spot, but you don’t need water to leak into your gauge cluster in order for it to get condensation in there. At the moment it just seems like you’re leaking and the moisture getting inside is just turning the car into a little rainforest.

A local body shop is probably the best place to inquire.

Thanks, guys. I should mention that I didn’t have any wet surfaces in the car after it rained, so it’s probably some sneaky little place that it’s leaking around the side or bottom of something. Is there any way I could check for where it is by myself? My FIL and I could probably do it if there’s a way…

Take a garden hose and run it around the car while someone is inside looking for leaks. It can be a door seal, a window seal, a trunk seal or any other seal… check your carpeting to make sure its not wet and dont forget to check the truck specifically in teh spair tire well.