Technically, a hot air balloon can fly in rain, but in 2026, it is considered highly unsafe and is never done commercially. The primary reason is the "boiling point" problem: the air inside the balloon's envelope is heated to roughly 100°C (212°F). When cold rain hits the top of the fabric, it creates an immediate cooling effect, causing the air inside to contract and the balloon to lose lift rapidly. To compensate, a pilot would have to burn significantly more propane, which risks damaging the fabric and exhausting the fuel supply. Furthermore, rain adds significant weight to the balloon system, making it sluggish and difficult to control. Visibility also drops during rain, and the moisture can lead to uncomfortable "drips" of dirty water from the envelope into the basket. In 2026, aviation safety protocols for ballooning are stricter than ever, and flights are cancelled if even light rain is forecast within the flight window to ensure a safe and dry landing for all passengers.