From stifling heat to thunderstorms, the Club World Cup has been at the mercy of the extremes of the American summer, with the threat of lightning now forcing players to retreat to the tunnels while fans seek shelter as matches are suddenly halted.

While soaring temperatures and oppressive humidity initially fuelled concerns among players and fans, it is the crackling skies and pouring rain that have emerged as the tournament’s most disruptive forces.

Friday’s match in Orlando between Benfica and Auckland City was suspended after halftime for nearly two hours due to a lightning storm in the area.

At the same venue on Tuesday, fans had barely settled into their seats when the referee ordered Ulsan HD and Mamelodi Sundowns to return to the dressing rooms, with the match delayed for more than an hour due to the threat of lightning.

Cincinnati witnessed an even longer interruption when a severe thunderstorm suspended Red Bull Salzburg’s clash with Pachuca for more than 90 minutes.

Palmeiras and Al Ahly saw their contest in New Jersey halted for 50 minutes due to lightning near MetLife Stadium.

“Your attention please. For your safety, we are going to have everyone leave the Seating Bowl area and take shelter inside the stadium because of severe weather in the area,” said a safety message flashed on the big screens in the arena.

“Event staff are available to guide and assist you. Those on the field, please walk calmly to the nearest tunnel… or to the service corridor.”

THREAT OF LIGHTNING

Heavy rain is often the X-factor for the home side on a cold, wet night in Stoke — which lends itself to the famous English soccer cliche — but the same cannot be said in the United States.

According to the country’s National Weather Service (NWS), 75% of lightning-related deaths in the last decade occurred from June to August.

Meteorological challenges are nothing new but with the combination of sweltering humidity followed by electrical storms, the simple yet stark warning from the NWS rings particularly true — “When thunder roars, go indoors!”

Tournament organisers FIFA have weather protocols in place to ensure the safety of those on the pitch and in the stands.

If there is lightning within 10 miles (16.09 km) of the stadium, an automatic match suspension is triggered.

The match director is informed, who in turn asks the referee to stop play. The storm is monitored before players are called back out, with the warm-up time before the restart dictated by the time they spent off the pitch.

Fans are also asked to leave the stands and find shelter in the concourse, with one source saying the stadiums had the capacity to keep them inside until the storm passed.