Severe thunderstorms snarl Heathrow and Gatwick operations, delaying 800+ flights

An intense line of overnight thunderstorms that followed a record 37.3 °C heatwave swept across south-east England in the early hours of 27 June, forcing National Air Traffic Services (NATS) to impose emergency flow restrictions at London Heathrow and London Gatwick. According to live tracking data compiled by FlightAware and quoted by airport officials, more than 400 departures and a similar number of arrivals were delayed at each hub, with some long-haul services pushed back by up to 11 hours and at least 100 flights cancelled. Airlines including British Airways, Virgin Atlantic and easyJet pre-emptively trimmed Saturday schedules, citing safety separations and ground-handling limits in lightning conditions. Heathrow’s operations centre urged passengers to “travel only after verifying flight status,” while Gatwick warned of knock-on disruption through the evening peak. Eurocontrol’s network map showed cascading delays across Amsterdam, Brussels and Paris as aircraft were rerouted around convective cells over the Channel. For corporate travel managers the episode is a timely reminder that weather-related disruption—formally outside EU261 compensation rules—can still trigger substantial duty-of-care costs. Employers with staff booked through self-service platforms should ensure that out-of-policy emergency accommodation and re-ticketing can be authorised quickly, and that travellers know how to reclaim subsistence expenses in jurisdictions that require original receipts. Forward-looking organisations are analysing ADS-B data feeds and subscription services that combine real-time meteorology with slot-allocation forecasts, allowing them to alert travellers before they leave hotels for the airport. Larger corporates are also revisiting ‘split-team’ crisis-response plans: when disruptions last longer than six hours, local-time fatigue management and mental-health support become material considerations. Although the Met Office lifted its amber thunderstorm warning by Sunday morning, NATS confirmed residual slot restrictions until 02:00 BST on 28 June, and airlines advised passengers to check itineraries for revised connections. Mobility teams with assignees transiting London over the coming days should continue to monitor arrivals, especially for flights requiring a landside re-check that could be affected by curfew infringements and crew-duty limits.