World Cup fixtures could face lengthy delays if they are interrupted by severe weather conditions as FIFA does not have a cut-off point in its regulations for calling a match off.According to U.S. thunderstorm protocol, a fixture taking place at a stadium must be immediately suspended if lightning or electrical discharge is detected within an eight-mile radius of the venue.The players are led off the pitch and must take shelter in their dressing room, while fans are evacuated to safe areas inside the venue.Once a lightning strike has been detected within eight miles, then a 30-minute countdown clock begins.And if this time passes without any further strikes, then the match can resume. However, if there is another lightning strike during that 30-minute window, then the clock is reset to zero, and it will continue to be reset until 30 minutes pass without a detected strike.Although FIFA is not responsible for U.S. thunderstorm protocol, nor can they override it, this could lead to World Cup fixtures being delayed for hours.FIFA does not have a specific regulation that stipulates how long a delay has to last before a match is eventually called off, although they will assess it on a case by case basis. Postponing a game would also create scheduling issues.