Wet rear passenger floor determined it's NOT the weather strip 02 accord honda

Car got sunroof?

if it has a moon/sun roof there are may complaints of this being the problem...Plugged moon roof drains can cause a water leak inside the car....

Look under the car for rust on the floorboard first, then dry the door jamb, close the door, and pressure wash (car wash) the window like crazy, making sure to get water underneath the weather seal at the bottom of the window. Open the door, and see if there is water poring out of the door panel afterwards, if so, remove the door panel, replace the weather barrier.