The author’s former home will shut on 10 April, also ahead of the Olympic Games when many tourist attractions are expecting boosted visitor numbers.
The museum has been awarded a Heritage Lottery grant of £2m.
Museum manager Shannon Hermes said the money was only available for a limited time and they had to seize the chance.
She added that there were already many Dickens-related events planned for London throughout the year.
See also the article ‘Why the Dickens are they closing this museum now?’ from the London Evening Standard