Townlands in Ireland were rarely named arbitrarily, and the word "Weatherfort" almost certainly derives from some older form referencing an earthwork, a rath, the kind of circular enclosure that early medieval farming families built across Ireland between roughly the fifth and twelfth centuries. That the townland should take its identity from such a structure, and that the structure itself should survive within it, gives the place a particular kind of continuity, a landscape that still echoes its own past in the most literal way possible.

A rath, sometimes called a ringfort, is a roughly circular enclosure defined by one or more earthen banks and ditches, built not as a military fortification in any grand sense but as a defended farmstead, a place to keep livestock secure and signal a family's claim to the land. Tens of thousands of them once existed across Ireland; several thousand survive in varying states of preservation. The one at Weatherfort is among the recorded examples in Mayo, a county whose boggy and rocky terrain has, in places, preserved such earthworks better than more intensively farmed lowland areas elsewhere. Beyond its classification and location, the documented detail for this particular site is limited, which is itself not unusual for smaller raths in rural Mayo, where the archaeological record can be thin on the ground even for features that have stood for well over a thousand years.