Climbing Adams Peak for sunrise in late May is the season basically over

The official pilgrimage season runs roughly December to May (peak around the Poya days), when the steps are lit, the path has tea stalls open, and crowds are large. Late May is the tail end. You can still climb off-season after that, but the lights and stalls are off, mist is heavier, and the summit temple may be closed, so a torch and warm layers are essential. Most pilgrims start the climb around 2am to reach the summit before sunrise (roughly a 3 to 4 hour ascent). The 5,200-odd steps are steep near the top; pace yourself and bring water.