An LED light fixture having a light-emitting region and a perimetrical structure therearound. The light-emitting region includes at least one LED-array module supported by an LED heat sink open for air/water-flow. The perimetrical structure has first and second opposite substantially-aligned edge-adjacent portions each extending along the light-emitting region and meeting each other at a perimetrical edge. The first and second edge-adjacent portions converge toward each other at positions progressively closer to the perimetrical edge to form aerodynamic-drag-reducing cross-sectional profiles transverse to the fixture plane and extending in substantially all fixture-plane directions from the intersection of its two major principal axes.