Every year, airports around the world experience thousands of hours of delays due to thunderstorms, costing airlines millions of dollars.
New research by Vaisala, a global leader in weather detection technology, suggests that these disruptions could be significantly reduced using data-driven scheduling. By analyzing over a decade of lightning activity, the study shows that thunderstorms tend to follow predictable patterns, allowing airlines to plan their schedules around high-risk periods.
Which Airports Face the Worst Lightning Delays?
The Vaisala lightning report, powered by Xweather Protect, examined lightning patterns at 50 of the world’s busiest airports. The findings reveal that airports in East and Southeast Asia, as well as major hubs in Florida, Texas, and the U.S. Midwest, are among the most affected by thunderstorm-related delays.
For example, Singapore Changi Airport experiences frequent afternoon thunderstorms during the inter-monsoon months of April, May, October, and November. Meanwhile, Dallas-Fort Worth International Airport sees peak lightning activity in May, but storms occur more evenly throughout the day.
By understanding when thunderstorms are most likely to occur, airlines can adjust their flight schedules, reducing the risk of cascading delays that disrupt global travel networks.
The balance between safety and efficiency for airports
Airports constantly balance considerations for safety and uptime. Lightning poses a significant risk to ground personnel and equipment at airports, but shutting down operations for a prolonged period comes with significant costs. In 2023, it was estimated that delays cost airlines alone as much as USD 100 per minute per plane.
FAA guidelines state that airlines should halt operations if a thunderstorm passes within a certain radius of the airport to ensure safety. A common alert condition is to cease operations when lightning is detected within a 5-mile radius of the airport. Airport activity only resumes after a set time with no further lightning, typically 10–15 minutes. This can lead to average downtimes of 30–60 minutes per lightning episode, depending on the alerting radius and the time it takes for a thunderstorm to move away.
There are no laws governing safety radius or all-clear times for airports, and different criteria impact the length of delays significantly. At an airport like Miami International, a 3-mile safety radius and 10-minute safety window after lightning passes would mean the airport would spend on average 4,373 minutes a year under lightning alert. However, a 3-mile radius would significantly reduce reaction time to halt operations and ensure personnel safety. With a 5-mile radius, the airport would have 6,737 minutes under alert, increasing delay costs but also ensuring safer operations.
“Airports are open spaces with large numbers of staff working outside and near structures that attract lightning. To keep personnel and passengers safe, operations are halted when a thunderstorm rolls overhead. The inevitable delays cost airlines millions each year and disrupt travel. Knowing when and where lightning delays are more likely can help airlines plan their schedules around these forces of nature,” says Ryan Said, Senior Lightning Scientist at Vaisala.
Data helps global aviation increase efficiency
Driven by diurnal heating and moisture availability, most of the United States has a higher chance of lightning activity in the afternoon through the late evening and during the summer months. Airlines can reduce the risks of delays caused by thunderstorms by scheduling routes through U.S. airports with lower lightning risk and having early morning flights during the peak lightning months of May through August.
With wild weather increasing with climate change, safe and efficient airports and airlines depend on reliable weather data. Vaisala data has been an integral part of global aviation for 50 years. Every single flight globally will at some point use weather data or forecasts derived from Vaisala sensor observations. Xweather Protect uses Vaisala’s extensive sensor network to track lightning events in real-time anywhere in the world, giving an accurate count, type and location of lightning strikes near each individual airport.
The full report includes individual airport profiles, a lightning risk ranking for the 50 busiest airports in the world, and an in-depth analysis of how airports can balance lightning safety and operational continuity. Read the full report here.
