Can the heat map symbology be applied to polygons in ArcGIS Pro?

Answer

No, the heat map symbology only applies to point features. It displays the relative density of points as a dynamic raster visualization with a range of colors. In ArcGIS Pro, the only way to apply the heat map symbology is to create a point from the polygon feature classes.

1. In ArcGIS Pro, navigate to the Contents pane and right-click the polygon layer.
2. Click Attribute Table and add new fields to the polygon feature class. Refer to ArcGIS Pro: Create a field and apply a domain and default value for instructions.
3. Use the Calculate Geometry Attributes tool to populate the new fields with the X and Y coordinates of each polygon. Refer to How To: Calculate geometry in ArcGIS Pro for instructions.

Note:
In Step 2 of How To: Calculate geometry in ArcGIS Pro, select the new fields for the Target Field parameter and the preferred property from the drop-down list in the Property parameter.

4. Add the X and Y coordinate data as a point layer using the XY Table to Point geoprocessing tool. Refer to ArcGIS Pro: Add x,y coordinate data to a map or scene for instructions.

Note:
Alternatively, it is possible to create the point feature class from the centroids or extents of the polygons. Refer to How To: Add point features to the centroid and the minimum and maximum extent of a polygon feature in ArcGIS Pro for more information.

5. Draw the point feature layer with heat map symbology to display the relative density of the points. Refer to ArcGIS Pro: Draw a layer with heat map symbology for instructions.