Flooding is causing difficulties for thousands of people in southern England after stormy weather lashed the UK.
Three severe flood warnings are in place in Surrey and Dorset, with many people rescued from homes overnight.
And some 50,000 homes across the UK are without electricity, the Energy Networks Association has said.
Gatwick Airport said it was running a full service, but advised people to check with airlines before flying after floods caused cancellations on Tuesday.
Armed police had to be called in to man information desks and deal with furious passengers who were stranded or delayed, one man told the BBC.
A spokeswoman said all flights apart from those with British Airways would be departing from the South terminal on Wednesday.
Risk of flooding
The River Mole in Surrey has burst its banks in several areas and an Environment Agency severe flood warning - which means a danger to life - has been issued for Leatherhead.
A severe flood warning has been issued for Iford Home Park, a residential development on the River Stour in Dorset, which police evacuated overnight.
People were also evacuated from the Beaulieu Garden Park Home in Christchurch, Dorset - where a further severe flood warning is in place.
The Environment Agency (EA) said the River Medway in Kent had continued to rise and flood risks would continue for three days, affecting areas including Tonbridge, Allington and Mereworth.
The Coastguard rescued 76 people from a flooded caravan park in Yalding on Christmas Eve, moving residents by boat and in four-by-four vehicles to a leisure centre.
In other developments:
- Some 150 properties have been flooded in England, mainly in Surrey and Kent, with numbers expected to rise - the EA has said.
- In Surrey residents were evacuated from their homes in Dorking, Leatherhead and Guildford, while more evacuations occurred in Tonbridge, Kent.
- Wiltshire Police say the historic Lacock Bridge has been washed away in the bad weather.
- Some 40 properties were evacuated in Godalming due to concerns about the River Wey.
- Firefighters in Surrey and Kent broke a five-hour nationwide strike to help deal with the effects of the storms.
- One hundred people booked in for Christmas dinner at the Wetherspoon's pub in Tonbridge, Kent had their plans disrupted after the restaurant flooded and managers had to send customers elsewhere.
- Distributor UK Power Networks is offering to pay for Christmas meals in local pubs or restaurants for people whose supplies remain cut off.
- On the roads, many major routes were flooded or blocked in Kent, Hampshire, Surrey, Sussex and Cornwall.
- In Dorset, fire crews rescued 25 people trapped in their cars by flood water.
- The Isle of Man Steam Packet ferry crossings says it is taking the unusual step of operating a Christmas Day sailing following cancellations during the day.
- Airline easyJet says it is operating a limited number of flights from Gatwick Airport to replace ones that should have operated on Christmas Eve.
- Tim Field from the Energy Networks Association said engineers were working to restore power to some 50,000 people still cut off in the east and south-east of England.
- Southern Electric said some 19,500 customers, most in south Hampshire, Surrey and West Sussex, could remain without power overnight.
- People are without power in the Wigton area of Cumbria, but Electricity North West said most should be reconnected by mid-morning.
The power cut at Gatwick's north terminal was caused by flooding on the Mole which affected airfield substations and saw more than 30 flights cancelled and police called in to man information desks.
Around 100 flights are due to leave Gatwick on Christmas Day - including some services rescheduled from Tuesday - and passengers are advised to check with their airlines before setting off for the airport.
Joe Pattinson, 35, from Wokingham in Berkshire, had been due to fly from Gatwick to Barcelona but ended up returning home amid the "absolute confusion".
"We'd been waiting for three hours in the queue. There was no information and we couldn't find anyone to explain what we should be doing. Eventually three armed police turned up to try and calm people down."
Jamie Whiteford arrived at Gatwick at 05:30 on Christmas Eve and spent more than 12 hours waiting at the airport for his flight to Edinburgh to depart before it was eventually cancelled.
"Eventually all [flights] were cancelled and this caused angry scenes at a flight to Naples which involved a police presence and very confused and untrained staff."
Meanwhile, about 800 homes in the north of Scotland are still without power, mainly around the Deeside area, Buchan, Elgin, Wick and the Western Isles.
Scottish Hydro Electric Power Distribution said about 400 of its staff are working to reconnect the properties this evening.
Winds gusting up to 80 mph caused disruption to Christmas travel in Scotland, with the Northern and Western Isles hit by ferry and flight cancellations.
There has been heavy rain in Northern Ireland, while winds in Wales have reached 78mph in Pembrey and 77mph in Aberdaron.
More than 10 flood warnings remain in place across mainland Scotland, with high tide being accompanied by heavy rainfall, but the number is beginning to fall.
The Environment Agency has more than 100 flood warnings in place for England and Wales - signifying that flooding is "expected", and more than 200 flood alerts, where flooding is "possible".
Winds are expected to ease today, before heavy rain and gales pick up again on Friday.
Kirk Waite from the Met Office said: "We do have a few showers around and they could be heavy at times, and some of them might bring more hail."
But he said the storm coming on Friday was not expected to be as severe as storms earlier this week.