The spackle compound is not intended for exterior use.
Make sure you use a caulk or sealant with silicone due to the expansion and contraction that the filler will go through thoughout the seasons. Most of these are paintable, but read the label to make sure.
If there is noticable wood rot around the hole, then clean out all of this before starting. You'll just be revisiting this same problem until you fix it right.
If this gets to be a larger hole, then you'll need to use something more designed for filling exterior holes