Wheeling has four proper seasons. Summers are warm and humid, with temperatures often reaching the high 20s Celsius; the river setting means it can feel muggy in July and August. Spring (April–May) and autumn (September–October) are the most pleasant times to visit, with cool temperatures and the Ohio hills in full color in fall.
Winters are cold and grey, with snow most years, but the city is not unpleasant in winter — Oglebay Park's Winter Festival of Lights, one of the largest in the country, runs from mid-November through January and draws visitors specifically for the spectacle. If you're travelling in winter, plan around that.