Hillingdon Council said this is what people living to the west of the airport would face, based on what it called “previously unpublished Department for Transport figures”.
There would also be noise from 25 potential departures in the same period, if the plans are approved, officials said, meaning disturbance from 63 flights in total.
Hillingdon Council is part of a cross-party campaign fighting the Government’s Heathrow expansion plans. The London Mayor has pledged support for a legal challenge.
MPs have voted in favour in Parliament tonight, with the Government winning despite impassioned pleas against - including from Hayes MP John McDonnell.
The DfT figures showed that as many as 35 flights could arrive before 5am, along with 25 take-offs, Hillingdon Council said.
Data compiled for the DfT shows that if a three-runway airport is to maximise its capacity, it would need to start operating with 38 aircraft an hour landing from 4am, according to Hillingdon Council.
And it said there would be a further 38 arrivals between 5am and 6am.
Currently people in south and west London suffer noise from around 15 or 16 flights every morning before 6am, when the airport is operating on westerlies, Hillingdon officials said. Aircraft land in this direction for around two-thirds of the year.
Hillingdon has support from leaders of Wandsworth, Richmond, and Windsor & Maidenhead councils for a possible judicial review, if proposals go ahead.
Cllr Ray Puddifoot. Leader of Hillingdon Council, said: “The ill-health consequences of a third runway are frightening. If it’s not worsening air quality from increased road traffic, it’s disruption to sleep patterns from early morning noise.
“The Government has failed to assess the true health impacts from expansion and it has failed even to identify which communities will be affected.”
He said: "Throughout the whole consultation process, the Government has failed to address the concerns not only of the impacted communities but also the advice from the Transport Select Committee. Now is the time for councils and groups to come together to stop this in the only way left to us - the courts. We are delighted the Mayor is joining and urge other boroughs to do the same.”
If MPs vote in favour and the Government moves to formally designate the National Planning Statement supporting the third runway project, the council allies will have six weeks to challenge the decision by way of a judicial review.
The four councils have long argued that existing noise levels and already poor air quality standards render a third runway “undeliverable and inconceivable”.
See the report here.
The DfT and Government have said Heathrow expansion is crucial for the economy and tourism.
Officials said there would be a “world-class package of compensation and mitigation measures to support those affected by the expansion, with up to £2.6 billion for compensation, noise insulation and community amenities, which could include improvements to parks and leisure facilities” if it goes ahead.
A statement read: “These are reinforced by plans for a 6.5 hour scheduled night flight ban and noise restrictions which will be legally enforceable.
“To make sure the whole of the UK benefits, the government has committed to about 15% of slots for domestic routes. While many of these will be delivered commercially, government has for the first time set out that it would use public service obligations to ensure existing and new routes are safeguarded.
“This includes the potential for slots to be ring-fenced and exempt from air passenger duty, which can save passengers £26 on the cost of a return domestic ticket.”
The DfT added: “The government is confident that the scheme can be delivered within our obligations under the Climate Change Act, and development consent would only be granted on the basis that the new runway is delivered within existing air quality obligations.”