Hot air balloon flights are highly weather dependent. If the conditions are rainy, have poor visibility or high wind speeds then the flight is unlikely to go ahead. In terms of ballooning, winds at ground level above 9 kts (approximately 10 mph or 17 kph) can result in very unpleasant and potentially dangerous landings. There are other legal requirements on the minimum visibility and lowest allowable cloud level, which will affect the possibility of your flight going ahead. Most pilots will not only take the legal minimum weather conditions into account, but also whether the conditions will make for an enjoyable flight.