Thunderstorms can bring air travel to a standstill even when the storm itself is miles away. In late June, more than 900 flights at London's Heathrow and Gatwick airports were delayed for up to 11 hours, and dozens were cancelled, after severe thunderstorms swept across south-east England and parts of Europe. Passengers were left stranded, with some waiting hours for updates. But the disruption wasn't random — it stemmed from how air traffic control must handle stormy weather.
When thunderstorms develop, air traffic control services like NATS, the UK's provider, have to reroute planes around the affected areas. Lightning, turbulence and heavy rain make it unsafe to fly through storm clouds, so aircraft must avoid them entirely. That means they need to be spaced further apart, which reduces the number of flights that can safely operate in a given airspace. As NATS explained, this limits capacity and causes a ripple effect of delays and cancellations.
“Explains how thunderstorms cause flight delays and cancellations at UK airports, with practical advice.”
The delays at Heathrow and Gatwick were particularly severe because the storms were located in a key corridor for European air travel. Eurocontrol, the Europe-wide aviation agency, showed the most severe delays in airspace between south-east England and north-western Europe — exactly where the storm clouds were sitting. Flights from as far away as Santiago, Chile, were affected, with one British Airways arrival delayed by 11 hours.
This is not a unique event. The UK's weather can change rapidly, especially in summer when heatwaves give way to thunderstorms. Just days earlier, the UK recorded its hottest ever June temperature — 37.3C in Suffolk. The same unstable air that produced that heat then fuelled violent storms. For UK travellers, this means that even if the weather looks fine at your departure airport, storms elsewhere can still ground your flight. NATS noted that while UK airspace looked fine on the following Sunday, further thunderstorms in Europe could still cause problems for cross-continent routes.
So what should passengers do? Airlines and airports advise checking your flight status before travelling. During the June disruption, easyJet pre-emptively cancelled a number of flights from Gatwick and offered refunds and accommodation. Passengers stuck overseas, like one traveller stranded at Venice airport, had to wait hours for updates. The key is to stay in touch with your airline and not assume your flight will operate as scheduled.
Q: How do thunderstorms actually affect planes? Thunderstorms contain lightning, severe turbulence, hail and strong winds. Flying through them can damage aircraft and endanger passengers, so planes must go around them. This requires extra spacing between aircraft, which reduces the number of planes that can take off and land per hour.
Q: Can flights be delayed even if it's sunny at my airport? Yes. Air traffic control manages a network of routes across the UK and Europe. If storms block a key airway, planes heading to or from your airport may be held on the ground or forced to take longer routes, causing delays even if your local weather is clear.
Q: What can I do if my flight is delayed due to thunderstorms? Contact your airline directly for the latest information. They are responsible for rebooking and, in some cases, providing accommodation or compensation. Check your airline's policy before travelling. Avoid relying on third-party trackers alone; official airline updates are more reliable.
For now, NATS expects disruptions to continue as long as thunderstorms persist. The forecast showed further storms in Europe that could affect routing across the continent. While UK airspace may clear, European delays can still back up into British airports. Passengers should remain flexible and prepared for last-minute changes.