While I agree that it is most likely a clogged condensation drain, there could be another cause.
One cause could be a water leak somewhere around the windshield gasket and the water travels around the edge of the glass to the middle and drips from under the dash.
Another problem we had with my wife's Saturn Ion was that the segments of the heater/AC case was not sealed properly and the condensation was leaking through the seams of the case before it got to the drain. Saturn fixed the problem and it never occurred again.
...Rich