When you book a hot air balloon flight over the Bath area, even if you book it a day or two in advance, bear in mind the climate! Though the climate of the South West is one of the milder ones in the UK, it’s still typically British, and therefore tends to be unpredictable. The weather has more than one effect on hot air balloon flights.
Even if you book a hot air balloon flight the day before and look up the weather forecast, you still cannot be certain what the weather will do at the time of your flight. Hot air balloon pilots consult local weather reports that are supplied to aeroplane pilots. These are very localised and provide the pilot with information about the local air conditions at the altitudes at which hot air balloons fly.
Even if it is dry at the launch site, rain could be expected during the flight. If you are taking off from Victoria Park, it could be a sunny day with gentle winds, but Bath’s weather can change quickly. The pilot will cancel the flight if very bad weather is expected shortly, as risks are simply not worth taking.
The balloon is filled with hot air which expands and provides lift. The amount of lift is dependent on the difference between the temperature of the air inside the balloon and the air outside. When it is cooler, this difference is greater than in hot weather. In hot weather, more propane needs to be burned to warm the air more to provide the necessary lift.
Obviously, a balloon needs to fly higher than the buildings of Bath. The pilot makes sure that the balloon is at a suitable altitude to clear all objects on the ground, no matter how hot or cold it is.
If there is rain, it can be uncomfortable, as water will run down the balloon and drip into the basket.
Rain cools down the balloon so the pilot will need to use the burner more, but if the rain is heavy there is a danger that the propane gas that fuels the burner will run out. Also, excessive use of the burner can cause overheating at the base of the balloon, so if rain is expected, the balloon flight will be postponed.
Where the balloon travels to is dependent on the wind direction and speed. Your flight could go as far as Stonehenge or Bristol if the wind is blowing in the north-west direction, although north-easterly winds are more common in Bath.
The best wind conditions for balloons are gentle speeds. Winds above 12 mph will mean a cancelled flight. Pilots need to know wind speeds at all heights, because although there may be mild winds at ground level, they may be much stronger higher up.
A hot air balloon flight operates in what pilots define as FAA VFR conditions, which means that they need to be able to see a distance of at least one to three miles. This means that hot air balloons will not fly at night or in fog.
Hot air balloon flights are thrilling experiences, but safe and comfortable flights can only be made in dry, clear and low wind conditions.