Villanova Researcher Authors Comprehensive Look at Large Outdoor Gatherings and Severe Weather Risk

If Benjamin Franklin had modern climatological data to consult, he may have scheduled his famous kite and key experiment for July of 1753 in Philadelphia, instead of a month sooner.

July, after all, is Philadelphia's most active month for lightning strikes, noted Stephen Strader, PhD, associate professor of Geography and the Environment and severe weather geographer at Villanova University.

Lightning has been on Dr. Strader's mind recently. In Spring 2025, he and a colleague published a study in Weather, Climate, and Societywhere they developed a metric to comprehensively rank more than 475 "large outdoor gatherings" in the U.S. in terms of greatest lightning risk, weak (EF0+) tornadoes and strong or significant (EF2+) tornadoes. The rankings factored in time of year, frequency of events, attendance and capacity, which was then compared to tornado/lightning climatology data for the venue location.

With major outdoor events scheduled throughout the summer in Philadelphia, Dr. Strader recently reanalyzed his data to include gatherings like the FIFA World Cup, MLB All-Star Game and America 250 celebrations in the city. What he found was that many of these gatherings-when compared to other large outdoor gatherings across the country-are among the most likely to experience certain severe weather events.

"While it is too soon to predict what the weather will be like for each of these events, the climatology does suggest that if severe inclement weather threatens them, many people could be exposed to deadly hazards such as lightning and tornadoes," he said. "The key is for venue organizers, first responders and event attendees to be informed, not alarmed."

Preparedness Lessens Impact

Every year, thousands of sports games, concerts, fairs, parades and days at amusement parks occur without weather-related safety incidents. But every now and again one does, sometimes with tragic results.

In 2011, a spectator at Pocono Raceway was struck and killed by lightning in the parking lot after the race was halted due to weather. One year later, a sudden strong wind from an approaching storm collapsed a grandstand at the Indiana State Fair, causing seven fatalities and dozens of injuries.

The objective of Dr. Strader's research was to find what venues are most likely, comparatively, to experience these extremely rare worst-case scenario exposures. By doing so, he hopes that it will help venues and organizers to understand how they can plan, execute or update their preparedness and protocol, so that their impacts are less deadly when they do occur.

"The idea isn't to scare people," he said. "Most of these venues and entities know that they're at risk for inclement weather. My hope is that those who do have a plan in place re-evaluate them, and think, based on the climatology, how they can adapt. For those who don't, the goal is to make them aware of their risk so they can begin to plan.

"There's a mental side to this too. Every year that goes by where there's not an issue or incident, people get increasingly relaxed. It's a reminder to stay vigilant."

Many of the large outdoor gatherings that appear high in the research rankings do have robust protocols and infrastructure. For example, amusement parks score very high for lightning risk because they are open almost every day of the year to huge crowds, and many are located in states that experience frequent severe weather, like Florida and Texas.

"But places like Disney World have comprehensive preparedness plans-they have people hired to understand and be aware of these threats," Dr. Strader said. "Attendees have ample places to seek shelter."

The same is true, to varying extents with sporting venues, especially major professional sports stadiums. Even though gatherings held there may rank higher for these weather events, the chances of a catastrophe are lessened because of preparedness, protocol and infrastructure.

Where Dr. Strader is more concerned is with gatherings like parades and fairs, especially when they last for multiple days and/or draw large crowds.

"A state fair tends to be more 'mom and pop' at times, and they lack permanent infrastructure," he said. "Vendors set up in temporary structures and a lot of times there are no places for attendees to seek shelter when thunderstorms threaten. You're also dealing with a transient population-people who don't know the area, and don't know where to go when severe weather hits.

"Parades are kind of a free for all in that you can come and go as you please. This is one of the reasons venues take tickets-so they understand their capacity to deal with an emergency. But if you have a place that doesn't do that, it can be tricky."

How Philadelphia's 2026 Events Rank

So, what exactly did Dr. Strader find when factoring in this summer's events in and near the City of Brotherly Love, and what does it mean?

In terms of lightning risk, several events and venues rank in the 80^th percentile and greater for potential exposure compared to all other documented U.S. large outdoor gatherings. Citizens Bank Park, the host of the MLB All-Star Game in July, ranks in the 95^th percentile. America 250 celebrations on July 4 rank in the 94^th percentile, while FIFA World Cup events at Lincoln Financial Field rank 87^th in June and 94^th in July.

For tornado threats to all nationwide events, Citizens Bank Park tops all local functions in July at the 96^th percentile. The America 250 celebration ranks in the 95^th, FIFA World Cup the 94^th and MLB All-Star Game the 78^th percentile for tornado exposure in that same month.

According to Dr. Strader, lightning is often the bigger concern because it is far less predictable than tornadoes. While events are frequently canceled ahead of a credible tornado threat, they are less likely to be canceled due to the possibility of lightning.

"Although lightning [strikes] and tornadoes are not very common in southeastern Pennsylvania, the large number of people gathered for these events sets up a 'what if' situation where tens of thousands of individuals could be threatened by severe weather," he said.

"Based on these findings, venue operators and governing bodies should continue to develop risk reduction strategies aimed at improving lightning and tornado safety, especially as lightning and tornado hazard threats evolve over time and across geographic space."

It is not only operators and organizers who should be prepared. Patrons, he says, can also devise and enact their own personal preparedness plan in the event of sudden severe weather. Teaching children simple sayings such as "when thunder roars go indoors" and scoping out potential places for shelter can go a long way in the event of severe weather-especially at come-and-go, transient events like America 250 festivities.

"And if you see approaching clouds on July 4, maybe find another way to pay homage to Ben Franklin, and pull down your kite."