The weather is THE most important factor when it comes to flying a hot air balloon because the safety of pilots, passengers and crew must come first! How do we make a fly/ no fly decision based on the weather? These are a few of the factors that we have to take into consideration.....

Wind - windy/ gusty/ breezy, all words you never want to hear when planning a balloon flight and, the main reason why most flights are cancelled. Wind is one of the most important factors in ensuring safe ballooning; at take off, in flight and during the landing. For a safe balloon flight, surface winds must be less than 12 knots maximum during the hour after dawn or before dusk (when the winds tend to be at their lightest, most stable and therefore when balloons will try to fly).

When preparing for take off, we first need to inflate the envelope using cold air (before the burners are used to heat this air up and cause the balloon to rise) but, even the smaller balloon envelopes are still pretty big and in too high winds, act just like a sail. This causes the balloon to roll around and even though it would be tied to a vehicle at this point, it can pull and drag at the vehicle and be very dangerous.

High winds during the flight can cause issues with the distance the balloon will travel once it is in the air, especially as the winds aloft are generally stronger than the winds at the surface - even though, from the ground, that might not be apparent. Balloons travel with the wind so before take off, pilots will look at the wind direction & speed to get a (very!) rough estimate of where they may end up landing (as in townland area direction rather than specific field). If the winds are too high/ higher than anticipated, you could unexpectedly end up somewhere rather inhospitable for landing i.e. a town/ city or over water. This is why, when planning a flight, in addition to the ground wind speed, pilots will always look at the wind speeds at 500ft, 1,000ft and 2,000ft.

When it comes time to land, the balloon will come to the ground at the same speed as the wind propelling it and, as they don’t have brakes, the speed directly impacts the size of the landing area needed to bring the balloon to a complete stop and the force of the impact with the ground. In higher winds it is more likely that the basket will tip over and drag along the ground upon landing and although this is normal and can be quite fun at low speed, it really isn’t when it happens at high speed.

At the other end of the scale and although very rare, sometimes we are faced with the opposite situation - not enough wind to fly. If there isn’t any wind, the balloon simply won’t go anywhere once it is up in the air or you find yourself becalmed over a town-land with nowhere to land.

Rain - this one is very simple, if it’s raining or if there is a chance of rain, we DO NOT fly. From as far as 100 miles away, storms will draw winds towards them and as balloons cannot be steered away, we would be sucked in - as you can imagine, the middle of a storm is a very dangerous place for a balloon to be. Rain also means muddy fields and they are never fun to be trying to get out of after landing!

Visibility - balloons fly under what is known as VFR, Visual Flight Rules, this means we need to be able to see where we are going and remain in sight of the ground at all times so, no fog or mist or such like. Since we sometimes have to fly at minimum heights above the ground, this also means that the clouds have to be at a minimum height in order for us to be below them and able to comply with VFR.

Temperature - Balloons “work” by making the air inside the envelope hotter and therefore less dense than the air outside of it, this makes the balloon “lighter than air” and fly. The colder it is outside, the less heat it takes to fly and conversely, the hotter it is outside, the more heat it will take to fly. Some balloons cope better than others at flying in hotter temperatures. This aspect doesn’t tend to be as applicable as the other factors IRO flights in Ireland though.....!

In order to know all of the above we rely on weather forecasts provided by specialist agencies, unfortunately it is not always possible for them to get these forecasts 100% accurate - hence why sometimes it’s a MAYBE FLY and we all go and stand in a field and see what it’s like in person. It is always gutting to get a no fly forecast just for it to turn out to be a perfectly flyable morning/ evening but, as the saying goes; it is better to be on the ground wishing you were up there flying than up there flying, wishing you were on the ground!