Natural convection for vertical flat plate - not getting expected results

Hi - I am doing a simple vertical heated flat plate flow simulation but I'm not getting the results that I expected - please see screen shot. I wouldn't expect the coldest temp to be towards the top ? I've attached my model.

I've put in boundary conditions for top and bottom lids and also the heat source. I've specified gravity in the Flow wizard and set ambient air temp to 295 which is what I am trying to model - I set the global mesh quite high to 6 after thinking this could be the issue however result still seem strange. Bottom lid boundary value is set to inlet with velocity of 0 (which I will update to 3 m/s to model forced convection which my next model) top lid is set to environment pressure. Can anybody give me any tips please?

thanks,

SolidworksFlow Simulation