The Gulf emirate had hoped the 828m high Burj Khalifa would be a major stimulant to boost its tourism economy.
In recent weeks, thousands of tourists have lined up to buy tickets for viewing times often days in advance that cost more than $27 each - or $110 for a queue-jump pass.
But the closure will now prevent those tourists gaining entry to the observation deck and casts doubt over plans to welcome its first permanent occupants in the coming weeks.
Agents were accepting bookings for next week, though there has been no confirmation the tower will reopen then.
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828m - height
57 - number of lifts
169 - number of floors
1,044 - number of apartments
31,400 - tonnes of steel used
330,000 - cubic metres of concrete used
$1.5bn - estimated cost
95 km - the distance it can be seen from
10C - cooler at the top than the bottom
158 - floor where "highest" mosque is planned
76 - floor of "highest" swimming pool
12,000 - number of labourers who toiled
$5 - daily wage of a labourer
Tourists affected by the closure are being offered the chance to rebook or receive refunds.
The shutdown comes at a sensitive time for Dubai, facing a slump in tourism - which accounts for nearly a fifth of the local economy - while fending off negative publicity caused by more than $80 billion in debt it is struggling to repay.
"It was the one thing I really wanted to see," one Slovenian tourist said.
"The tower was projected as a metaphor for Dubai. So the metaphor should work. There are no excuses."
Dubai officially opened the skyscraper on January 4 in a blaze of fireworks televised around the world.
The building had been known as the Burj Dubai during its construction, but the name was suddenly changed on opening night to honour the ruler of neighboring Abu Dhabi.
Work is still ongoing on many of the building's floors, including those that will house the first hotel designed by Giorgio Armani that is due to open in March.
The first of around 12,000 residential tenants and office workers are supposed to move in this month.
The observation deck, which is mostly enclosed but includes an outdoor terrace bordered by guard rails, is about two-thirds of the way up on the 124th floor.