Weather to Fly or Not – That is the Question

Hot air balloons need the right weather conditions to be able to fly and depend on weather factors including wind speeds, visibility and more. Before a hot air balloon can lift off, the pilot must always first check the weather.

Can it be too windy to fly?

Balloons fly best in light and stable winds of 4-6 miles per hour. Maximum safe winds are 8-10 mph. Wind affects every phase of a flight. Here are the reasons wind is such an issue:

During inflation the balloon envelope is filled with cold air using a fan. The balloon fabric is like a giant sail, and winds approaching 10 mph make it almost impossible to fill the balloon, caving in the side and rolling the balloon around, sometimes violently.

Strong winds can take the balloon too far. Since a balloons flight path and the distance is determined by the wind’s speed and direction, this can be a problem.

High winds can carry a balloon into areas that are unsuitable for a landing—such as metropolitan areas, forests, restricted airspace or large bodies of water.

And then there is the landing. High wind speeds mean that the pilot needs a larger area in which to land. A balloon relies on the friction of the basket dragging along the ground to come to a stop as balloons do not have brakes.

What are winds aloft?

The winds on the ground may not even have a hint of a breeze but balloon flights may be cancelled due to wind. How come? Pilots look at winds at the surface (the wind you can feel) and the winds at 1 to 9,000 feet.  The balloons are not going to 9,000 feet, but it tells the pilot if they might encounter issues such as wind shear, turbulence, or strong surface winds later on. Even if there are no winds at the surface, the winds aloft may drive the decision not to fly. Winds aloft of 18-20 knots or 20 miles per hour can be sufficient to cancel a flight.

What is a pi-ball?

Winds may seem perfectly calm but balloon flights can still cancel because of high winds. Sometimes the wind is calm on the ground, but here can still be dangerous winds at higher altitudes. The pilots test the wind on the launch field with a pi-ball (a small helium party balloon to give us a visual representation of what the wind is doing). If it reaches treetop level and then shoots off very fast, this indicates a wind sheer and it may be too dangerous for a balloon to launch. It is also dangerous to try to land a hot air balloon in high winds.

How do pilots steer balloons?

Generally speaking, they don’t. A balloon drifts in the same direction and at the same speed as the wind. The skill is for the pilot to pick the altitude that has the most desired wind direction. Surface winds many times blow in a different speed or direction than the winds aloft.

Can you fly in the winter?

Yes indeed! As long as you are properly dressed (as you would if, for example, you’d be attending an outdoor football game), winter flying can be incredibly beautiful. The air is frequently clearer, and visibility much improved (25-50 mile visibility is often possible). Because trees are bare, it is also easier to spot wildlife. The only concern may be that access to landing sites may be more difficult if there is significant snow cover.

Can balloons fly in cold temperatures?

The temperature difference between inside and outside the balloon envelope determines the lift of a balloon, so balloons can fly well in cold weather. However, if the liquid propane in the fuel tanks is too cold it may become too cold for the propane to work.

What is visibility?

Visibility is how far can we see. Balloonist like to have visibility of at least 1 to 3 miles to fly. Visibility can be very difficult to predict and is probably the most commonly occurring error in weather forecasts. The different conditions to form mist, fog or low clouds can vary within a few miles.

When is the best time to fly?

Hot air ballooning is a year-round sport. Weather conditions for ballooning are best just after sunrise and 2-3 hours before sunset. Light, ideal winds (4-6 mph) often occur during these times. During the day, when the sun is high, thermals (large bubbles of hot air that rise from the sun-heated earth) make ballooning hazardous.

Where does the balloon land?

The balloon lands on the ground. Since the balloon travels with the wind, it is difficult to predict the exact landing site prior to the launch. However, a pilot is able to determine the general flight direction and landing area by studying the winds.

How do you get the balloon back?

Your chase crew driving a van or pickup truck helps get the balloon back. This chase crew follows the flight of the balloon (as well as the existing roads allow) and should be on hand to make the recovery when the balloon touches down.

How long can a balloon stay up?

It depends. Normally, the balloon carries enough fuel to remain aloft for 2 hours, but factors such as outside air temperature, weight being carried in the basket, and weather determine the duration of the flight.