Severe weather over Johannesburg has disrupted operations at OR Tambo International Airport, with arriving flights held in holding patterns and a number of aircraft diverted to Lanseria International Airport and King Shaka International in Durban.
As of 5:57pm local time, FlightRadar24 was listing OR Tambo as the most disrupted airport in the world, a live ranking the tracker calculates from the share of flights delayed, cancelled or diverted at each airport.
The disruption was forecast. On Saturday afternoon, the South African Weather Service issued a warning for the possibility of severe thunderstorms across Gauteng on Sunday, citing flooding, hail, gusty winds and excessive lightning. Thunderstorms are among the most disruptive conditions for an airport, because unlike fog they don't just reduce visibility. Lightning halts ground operations, since ramp staff can't safely work outside, and pilots avoid flying through active storm cells, which closes off approach paths even when the runway itself is usable.
⚠️ ALERT: THE SA WEATHER SERVICE HAS ISSUED A WARNING FOR THE POSSIBILITY OF SEVERE THUNDERSTORMS ACROSS GAUTENG ON SUNDAY. FLOODING, HAIL, GUSTY WINDS & EXCESSIVE LIGHTNING POSSIBLE IN PLACES
— Gauteng Weather (@tWeatherSA) September 5, 2026
Passengers on diverted flights are being held on board at those airports while airlines and airport operators work out how to get them to Johannesburg.
A flight attendant on one of the diverted aircraft, a Johannesburg-bound flight now on the ground at Lanseria, told Contrail that the aircraft circled for some time before the diversion, and that passengers on board are frustrated at being kept on the aircraft with no clear timeline.
What's happening
When storms sit over an airport, air traffic control has to route arrivals around the active cells and space them further apart, which cuts the number of flights that can land each hour. If lightning is close enough, ground handling stops entirely. Aircraft that can't be sequenced in are put into holding patterns, and once fuel or crew duty limits come into play, they divert.
Lanseria, about 45 kilometres north-west of Johannesburg, is the usual first alternate for OR Tambo and has absorbed diversions in previous weather disruptions this year. Durban is around an hour's flying time away, which means passengers diverted there face a much longer wait to reach Johannesburg, or a change of plans entirely.
Diverted aircraft often can't let passengers off. The alternate airport may not have the gate space, ground handling, or immigration facilities to process an unexpected arrival, particularly an international one, so passengers sit on board until the aircraft can either continue to Johannesburg or the airport arranges to disembark them.
If you're flying today
Check your flight status directly with your airline before travelling to OR Tambo. If you're meeting an arriving passenger, confirm which airport they actually landed at before setting off. Lanseria is a long way from OR Tambo by road.
If you're on a diverted aircraft, stay in touch with the crew about disembarkation. In extended ground delays, airlines are generally expected to provide water and, where possible, food.
