A severe thunderstorm on 30 June 2026 forced 40 aircraft to divert from Zurich Airport, causing 44 cancellations and 70 total flight annuls by 07:00 on 1 July 2026. The storm suspended all takeoffs and landings for two hours, forcing landing approaches into holding patterns before diversion to Stuttgart, Geneva, Basel, Lyon, and Milan. Swiss International Air Lines faced critical crew and aircraft mispositioning, triggering cascading cancellations as operators struggled with no hotel availability for stranded passengers. Over 25,000 lightning strikes recorded by SRF Meteo flooded streets and cellars, while a second storm at 06:00 forced landings on Piste 16. This event underscores operational risks for short-haul European aviation during summer thunderstorm seasons, demanding rigorous logistics management when diversions occur.