At the moment in the dashboard, If there is no input (data) for a widget in the dashboard then it looks blank so is it possible to not show that widget if there isn't any data for any specific widget. This is based on the customer request.
As an alternative it is possible to use the Minimum N setting in the widget. If there is not enough data, the widget will be greyed out with notification stating that there is not enough data:
To use this option, open the bar chart in edit mode and go to the Display point tab.
Fill the 'Minimum N to include in the compare' with the minimum amount of your records that you want to be there, and save the widget.
If you put this setting to '1', it will ensure that the widget is greyed out if there are no records available, and as soon as a single record comes in for that period, the widget is activated again.