It sounds like the door(s) weather seals are leaking.
Try this A. sit in the car with the doors closed and the windows rolled up on a rainy day and feel on the cars floor for water,,and feel all around the the doors and the windows seals for where the water may be entering. B. sit in car like before but have a helper,,using a spray nozzle,,spray water around the door seals to see if water gets inside.
You may need to replace one or more seals if they are torn, damaged, or otherwise deteriorated.
3M sells a product called 3M Weather Seal Adhesive,,its avail. in clear and black,, The black can be used to repair torn or cut weather seals,,and the clear can be used to attach weather seals to body/door panels.
This product can be found at professional auto body specialty paint stores.