Kiwi.com Flight Disruptions Report: September 2025
Kiwi.com, a global travel technology company focused on solving the key anxieties of air travel, shares the findings of its latest report into the major causes of disruptions to flights.
Kiwi.com’s September Disruptions Report shows a 0.26 percentage point increase in the disruption rate in September compared to the same period in 2024, resulting in an overall rate of 1.69%. Though the impacts on flights from the conflict in the Middle East lessened, September saw increases in both the airline operational issues and industrial action categories, along with disruptions caused by a cyberattack affecting several major European airports.
“The ransomware attack in September caused widespread disruptions to automated check-in and boarding systems at European airports, including London Heathrow and Brussels airports, forcing airlines to use manual workarounds which resulted in flight delays, cancellations, and the involvement of law enforcement in the investigation,” said Tom Parry, Head of Business Resilience at Kiwi.com.
Top causes of flight disruptions1 | September 2025
| KEY CAUSES OF DISRUPTIONS | % OF TOTAL 2025 | % OF TOTAL 2024 | YoY ⬆️⬇️ |
| Industrial Action | 21.29% | 6.33% | +237% |
| Geopolitics/War/Terrorism | 16.96% | 39.23% | -57% |
| Airline Operational Issues | 8.92% | 0.90% | +893% |
| Uncategorized | 5.71%2 | 0.93% | +513% |
| Weather | 2.06% | 5.20% | -60% |
| Airport Closures | 0.45% | 0.78% | -43% |
| ATC restrictions | 0.00% | 0.00% | 0% |
| Government Regulations | 0.00% | 0.00% | 0% |
| Natural Disasters | 0.00% | 0.00% | 0% |
1) Based on the number of Kiwi.com passengers affected by flight disruptions
2) In September 2025, this was the case of a ransomware attack responsible for widespread disruptions to automated check-in and boarding systems at several major European airports, including London Heathrow and Brussels. The cyber-attack targeted the Arinc cMUSE software provided by Collins Aerospace, forcing airlines to use manual workarounds and resulting in flight delays, cancellations, and the involvement of law enforcement in the investigation.
The impacts of Industrial Action grew again, following a rise also in the previous month with the Madrid Airport security personnel strike, the national strike in Italy, baggage handling strikes in Portugal, and the nationwide strike in France all impacting flights in September.
In the airline operational issues category, which includes events such as airline insolvency, there were several issues that came together in the same month. The rise in this category’s position in the disruptions table was predominantly caused by Icelandic low-cost carrier, Play ceasing operations.
“September was especially eventful in regard to operational issues, with the impacts of Spirit Airlines filing for Chapter 11 Bankruptcy Protection for the second time in a year, Play ceasing operations, Braathens International Airways filing for bankruptcy, and Cabo Verde Airlines experiencing operational issues,” added Tom Parry, Head of Business Resilience at Kiwi.com.
A Czech customer of Kiwi.com experienced a disruption of their booked flight to Reykjavik due to Play airlines ceasing operations. His trip was saved by the Kiwi.com Guarantee: “My flight was canceled because Play Airlines went bankrupt. Kiwi.com responded immediately and offered several solutions. A few days later, I flew with another airline without paying anything extra,” the happy customer shared in his feedback.
The Kiwi.com Guarantee gives travelers the flexibility to receive instant credit refunds for disrupted or canceled flights, regardless of the carrier, allowing them to rebook without delay. For the month of September Kiwi.com’s Guarantee supported customers affected by these disruptions, providing over 1.2 Million euros to affected customers so they could immediately replace disrupted flights.
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Categorization of causes of flight disruptions
For the purposes of this report and further internal analyses, the various events causing flight disruptions are grouped into multiple categories, which are designed to be as comprehensive as possible. In September, the following types of disruption events were recorded by Kiwi.com:
- Industrial Action
Any disruption event caused by either airport or airline staff strikes. In September, examples of tracked events included the Ryanair strike in Spain, Madrid Airport security personnel strike, the national strike in Italy, baggage handling strikes in Portugal, and the nationwide strike in France. Kiwi.com tracked 15 similar events in September.
- Geopolitics/War/Terrorism
Besides the cases related to the ongoing Middle East conflict, which for the first time were lower in numbers than last year, we have seen airport and partial airspace closures due to unauthorized drone incursions in Poland, Oslo, and Copenhagen.
- Airline Operational Issues
This includes events such as airline insolvency resulting in flight cancellations or canceling previously announced (and sold) routes. September was especially eventful in this regard, when Spirit Airlines filed for Chapter 11 Bankruptcy Protection for the second time in a year, Fly Play (OG) ceased operations, Braathens International Airways (TT) filed for bankruptcy, and Cabo Verde Airlines experienced operational issues. Especially the Spirit Airlines and Fly Play situations will also impact the planned customers’ travels in October.
- Uncategorized
In September 2025, a ransomware attack caused widespread disruptions to automated check-in and boarding systems at several major European airports, including London Heathrow and Brussels. The cyber-attack targeted the Arinc cMUSE software provided by Collins Aerospace, forcing airlines to use manual workarounds and resulting in flight delays, cancellations, and the involvement of law enforcement in the investigation.
- Weather
In September, major disruption events in this category included Typhoon Ragasa in Hong Kong, severe weather in Barcelona, Hurricane Gabrielle in the Azores, Storm Amy in Dublin, and unfavorable weather conditions in Brussels and Amsterdam airports.
- Airport Closures
Such as the closure of Tribhuvan International Airport in Kathmandu due to escalating anti-government protests across the Kathmandu Valley on September 9, 2025, or the temporary airspace closure around Kuala Lumpur International Airport in conjunction with Malaysia’s 68th Merdeka celebration.
- Government Regulations
For example, changes in governmental policies, such as the US president’s proclamation banning travel to the US from 12 countries signed on June 5 and going into effect on June 9, were still affecting Kiwi.com customers in July.
- Natural Disasters
Events such as wildfires, earthquakes, volcanic eruptions, tsunamis, mudslides and landslides, or extreme flooding.
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