Season geography
Across West Virginia's featured cities, typical openings spread from May 17 to May 31, closings from Sep 17 to Sep 24, and the unheated season runs 109–130 days depending on where you are. Elevation, coastal water, and urban heat all pull real dates around, which is exactly why a state-level answer isn't enough.
For your exact town, the pool season lookup takes a ZIP code. Opening day itself is a chemistry job — the dosing calculator turns your first test reading of the year into exact amounts.