Mount Bromo in June

April through October offers the clearest skies and minimal rain. July and August are peak season - expect crowds and higher accommodation prices. May and September hit the sweet spot with good weather and fewer tourists. Avoid November through March unless you enjoy hiking in the rain. The wet season brings thick clouds that obscure the crater views you came to see. Plan your visit around the new moon for the best stargazing. The lack of light pollution here is remarkable, but only if clouds don't roll in. Check weather forecasts obsessively - one cloudy morning can ruin the entire experience.