Loaded Lightmaps Clearing On Play

I am working on an editor tool that will allow 3D artist to load in lightmaps baked in external programs. I had the system working as two scripts that ran things on Awake - one to create the lightmaps, and the other to apply to certain renders.

However, I decided it would work better to be an editor tool that way so many things aren't happening when a scene initializes.

The problem is that once the lightmaps are loaded into the lightmap arrray (which I can see in the "lighting" tab) and I hit play, all the data is gone. Why is this data getting cleared? Do I really need to only do this in runtime?

Here is a sample of the code:

LightmapData mapdataSave = new LightmapData();
mapdataSave.lightmapNear = tempNearMap;
mapdataSave.lightmapFar = tempFarMap;

currentLightmaps.Add(mapdataSave);

LightmapData[] currentLightmapsArray = new LightmapData[currentLightmaps.Count];
for (int i = 0; i < currentLightmaps.Count; i++)
{
currentLightmapsArray = currentLightmaps;
}

LightmapSettings.lightmaps = currentLightmapsArray;