Clipping Heat Maps

[IsaacSuh]

I am currently working on a heat map and wanted to do a pairwise clip to limit the radius of the heat map points to within the boundaries of a city. Whenever I run the clip tool or pairwise clip tool it does nothing to clip the edges of the heat map that are spilling outside the boundaries. Does anyone have any alternative ideas to prevent the heat map from spilling outside of the boundaries?

[DavidSolari]

If you're rendering the map in Pro, you can go to the Map's properties and fiddle with the Clip Layers section. This'll create a clip mask that you can apply to layers, including the output of the Heat Map symbology. Here's an example of what this looks like from a layout I made: 

If you don't have Pro or you have the heat map as a raster then you'll need a tool that can clip rasters, not sure what the workflow is there.