The weather they refer to is the wind causing flow restrictions.
Found this on the euro control website.
EGLL (London Heathrow) arrivals
regulated due to weather (strong winds).
Delays are high.
EDDH (Hamburg) arrivals
regulated due to weather (TS).
Moderate delays.
EHAM (Amsterdam) arrivals
via entry cross border regulated due to weather (CB).
Moderate delays.
LTFJ (Istanbul/S. Gokcen) arrivals
regulated due to aerodrome capacity.
Moderate to high delays.
LTBA (Istanbul/K. Ataturk) arrivals
regulated due to aerodrome capacity.
Low to moderate delays.
So the truth has been told.