Hundreds of flights were delayed on 24 June 2026 when thunderstorms swept across London, affecting both Heathrow and Gatwick airports at the same time, according to BBC Weather.

When both airports have problems at once, passengers cannot easily switch flights, and planes fall behind schedule for all the flights that were supposed to follow. Heathrow handles most of the UK's long flights to other countries. Gatwick handles shorter trips and holidays. The disruption meant nowhere else to go for stranded passengers.

Gatwick has a particular problem: it has only one runway. It is the world's busiest single-runway airport. According to Gatwick, it is designed to handle one plane every 65 seconds. A 30-minute weather delay means roughly 27 scheduled flights cannot take off or land. Because Gatwick's schedule is already packed to capacity, those 27 flights do not disappear — they back up into the afternoon and evening, affecting every other flight planned for the rest of the day.

Heathrow has two runways, so it has more breathing room, but it too runs near its maximum most days. Thunderstorms force air traffic controllers to spread planes further apart as they land and take off. This reduces how many planes can move through each hour. The result is fewer flights and longer delays.

It was also late June, the start of peak summer travel season. Planes were fuller than usual. That meant more passengers affected by each delay, and more work for ground staff managing hotel rooms, rebooking queues, and compensation rules.

Thunderstorms are a seasonal risk for UK airspace, but forecasting exactly where and when they form is hard. The Met Office can warn that storms might happen hours before they arrive, but it cannot predict where individual storm cells will develop or how they will move until they are very close. Airlines and air traffic controllers plan for disruptions based on forecasts, but when storms form faster or move differently than expected, those plans change on the fly. A brief storm in one area can still cause delays for twelve hours or more once the backlog spreads through the network.

There is a broader issue that airport planners think about. Gatwick cannot build a second runway due to planning restrictions. That single-runway limit is not new, but this disruption shows why it matters: when there is no extra capacity, there is no cushion when something unexpected happens.

For passengers stuck in those delays, the main question is whether they can claim compensation. UK261 rules allow compensation for delays over three hours on arrival, unless the delay was caused by something extraordinary — like weather. Airlines often use this excuse, though courts have started to push back. If the airline or airport could have handled the weather better, the weather excuse does not always work.

The storms passed. The flight schedule delays took much longer to clear.