Around 170 UK flights had been cancelled as of early Sunday morning but that number has risen throughout the day.
Heathrow has suffered a further 26 cancellations and 133 delayed flights as the chaos continues while Gatwick axed another 16 with 68 disrupted.
Gatwick Airport urged customers to set off from home early to make their flights amid disrupted rail and road routes.
About 60 per cent of flights were disrupted coming into and out of the Heathrow, while Gatwick experienced about 30 per cent, according to Travel news service Inrix.
Shocking footage captured at the London airport shows a pilot trying and failing to land during the horror weather.
It came as the Met Office issued "danger to life" warnings as gales continued to rage across the country.
A rare red weather warning for rain was issued for parts of Wales as dramatic images show the flooding from Storm Dennis wrecking havoc.
Other clips show planes landing at Birmingham Airport, descending slowly as they battle the winds.
ABORT, ABORT ABORT
Several jets shook and swayed in the air above the airport but managed to touch down safely.
Others bounced on the runway after landing but despite the frightening scenes the planes were able to land successfully.
EasyJet has cancelled about 118 flights, while British Airways has axed around 50.
Virgin cancelled four long-distance flights from Heathrow to Hong Kong and Boston scheduled for yesterday and today.
Meanwhile, British Airways confirmed 40 short-haul flights to and from Heathrow last night and this evening had been cancelled, with routes to Amsterdam and Glasgow the worst affected.
The Met Office has said the storm has become "life-threatening" in South Wales.
It comes as two people were found dead yesterday in rough seas.
Forecaster Greg Dewhurst said: "It's quite an extreme move but we have seen widespread falls across the whole region."
Severe flood warning were issued for the Scottish Borders and for the River Neath in South Wales as images showed how the River Taff had burst its banks at Pontypool.
Homeowners say they received flood alerts at 4am telling them to take immediate action and move to safety.
One mum-of-two said: "I was woken up by a phone call and then had a voicemail saying to get to safety.
"It was really frightening as I've never experienced flooding like this before."
