Data-driven flight scheduling can significantly reduce the risk of thunderstorm delays
Vaisala
Press release
March 19, 2025
Data-driven flight scheduling can significantly reduce the risk of thunderstorm delays
Every year, major airports serving tens of millions of passengers spend thousands of hours under lightning alerts, often halting operations and causing costly delays. However, analysis of data spanning more than a decade shows that these disruptions tend to follow predictable patterns. A first-of-its-kind report from global lightning detection leader Vaisala shows that thunderstorms occur more frequently at specific times and months, meaning airlines can plan their schedules to reduce costs and the related domino effects on flight transfers.
Vaisala, a global leader in measurement technology, today published a first-of-its-kind lightning report for global aviation. The report is based on insights from Vaisala Xweather Protect, an all-in-one solution for weather risk management, real-time storm monitoring, and alert automation.
The report gives in-depth insights into lightning activity at the world’s 50 busiest airports. It reveals that airports in East and Southeast Asia, as well as large U.S. hubs in Florida, Texas, and the Midwest, experience high lightning activity at specific times of the year and day.
Knowing when lightning is most likely to occur can help airlines schedule their flights to avoid high-risk periods during months with high lightning activity. For example, Singapore Changi Airport experiences a high number of thunderstorms that occur mostly during the inter-monsoon months of April, May, October, and November, and mostly in the afternoon. Conversely, Dallas-Fort Worth International sees lightning activity peak in May, but with a more even distribution throughout the day.
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 an average of 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 the availability of moisture, 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.
###
More information for the media
Ryan Said, Senior Lightning Scientist, Vaisala Xweather
ryan.said@vaisala.com
Katri Koponen, Communications Manager, Media Relations, Vaisala
katri.koponen@vaisala.com
About Vaisala
Vaisala is a global leader in measurement instruments and intelligence for climate action. We equip our customers with devices and data to improve resource efficiency, drive energy transition, and care for the safety and well-being of people and societies worldwide. With almost 90 years of innovation and expertise, we employ a team of close to 2,500 experts committed to taking every measure for the planet. Vaisala series A shares are listed on the Nasdaq Helsinki stock exchange.
Vaisala Xweather brings weather confidence to decision-makers in every weather-sensitive business. We combine local sensor data with advanced AI predictions to deliver precise and actionable weather insights. Vaisala Xweather transforms weather challenges into opportunities to optimize safety and efficiency while improving resilience against severe weather and climate change.
Attachments
- Lightning risk by time of day, Dallas vs Singapore
- Lightning risk by month, Dallas vs Singapore
- Ryan Said
