If there is any confusion as to the reason your flight is canceled, do view the app/ flight status/ flight number function. If it mentions "apologies ..... adverse weather.." that is the reason and it will be listed everywhere internally as such. The app gets its updates this way. If the word weather does not appear it will be for some other reason.
Meanwhile for the European network it is shaping out to be a wonderful Monday afternoon;
Aerodrome
EGLC (London City)
Arrivals regulated due to Weather (Strong winds)
Moderate to high delays
EGLL (London Heathrow)
Arrivals regulated due to Weather (Strong winds)
High delays
EHAM (Amsterdam)
Arrivals regulated due to Weather (Strong winds)
High delays
LEBL (Barcelona)
Arrivals regulated due to low visibility.
High delays
LFSB (Bale)
TMA regulated due to ATC Staffing
High delays
LFML (Marseille)
Arrivals and TMA regulated due to ATC Staffing
High delays
LPPT (Lisbon)
Arrivals regulated due to Airspace Management
Moderate to high delays
GCLP (Las Palmas)
Arrivals and depatures regulated due to AD capacity.
Moderate to high delays.
Airspace
EDWW (Bremen)
Mark & Mueritz sectors regulated due to Airspace Management
Low delays
LECP (Palma)
ALP sector zero rate regulation cancelled.
GCCC (Canaria)
Central collapsed sector regulated due to Atc capacity.
Moderate delays.