Hillary Clinton raised $63 million in the month culminating in the Democratic National Convention last week, her campaign announced on Tuesday, her most successful fund-raising month to date.

Clinton officials also said the campaign received a surge of money in the 24 hours after Mrs. Clinton’s speech Thursday accepting the nomination, with $8.7 million raised. Mrs. Clinton also raised $26 million in July for the Democratic National Committee, money she is certain to benefit from now that she is formally the Democratic nominee.

Mrs. Clinton began August with $58 million in the bank, a figure that suggests she will maintain or expand her financial lead over Donald J. Trump, the Republican nominee. At a rally on Monday, Mr. Trump said his campaign had “raised with small donors $35.8 million. I believe it’s 517K donors.”

That figure would represent a substantial influx of small-donor money for Mr. Trump. The candidate did not specify whether that figure applied only to his campaign or to his joint fund-raising operation with the Republican National Committee. His campaign did not respond to a request for more information.