Try an auto roof to see if it stops the rain from falling as I can see in the second picture there looks like there could be a hole between the smaller roof on the side and the larger roof covering most of the house. It can be tricky and you have to look at a roof from the top down (use the arrow to look straight down on a roof. You do mean rain falling in the house from a hole correct and not because you aren't scrolled in close enough, correct?
Origin last patch does not fix the game, it removes EA Info tool and Securom (which are both incompatible with Windows 10) from the code. No patch from Origin actually patches TS2.
My best advice, remove the roof, and any tile you placed and use Auto Roof since you can't find the hole. Also if you ever build your own chimney you have to put tile on the top of those or down inside it so it won't rain in the house. Towers, chimney, etc.
Most of Maxis houses/roof will leak and everyone had to go back after Seasons and fill in some holes (no flooring) in most of Maxis houses if you use a premade house later.
You can also pick Flat Roof and tile all of that if you don't like the color of the flat roof.
ETA: If you mean it looks like it's raining inside your Sim house, or leaf falling, in TS2 you have to scroll in pretty close for the camera to stop showing those effects.
