CHARLOTTE, N.C. – Senator Barack Obama’s grandmother, a central figure in his life who helped raise him during his teen-age years, died in Hawaii on Monday morning.

Mr. Obama, who left the presidential campaign trail late last month to travel to Honolulu to bid her farewell, announced the death in a statement released by his spokesman upon landing here this afternoon. Her death comes one day shy of Election Day.

“It is with great sadness that we announce that our grandmother, Madelyn Dunham, has died peacefully after a battle with cancer,” Mr. Obama said in a statement. “She was the cornerstone of our family, and a woman of extraordinary accomplishment, strength, and humility. She was the person who encouraged and allowed us to take chances.”

Madelyn Dunham, who turned 86 on Oct. 26, was unable to travel to see her grandson on the campaign trail. But from her apartment in Honolulu, she religiously followed his bid for the presidency, tracking his movements and his progression through cable television.

Mr. Obama learned of his grandmother’s death a little after 8 a.m. in Jacksonville, Fla., where he had spent the evening, said Robert Gibbs, a senior adviser. Mr. Gibbs said that Mrs. Dunham died late Sunday evening on Hawaii Standard Time, which was between 4 and 5 a.m. on the East Coast.

“She was proud of her grandchildren and great-grandchildren and left this world with the knowledge that her impact on all of us was meaningful and enduring,” Mr. Obama said in the statement. “Our debt to her is beyond measure.”

Mr. Obama released the statement with his sister, Maya Soetoro-Ng, who has been at Mrs. Dunham’s side while Mr. Obama has been campaigning for president.

“Our family wants to thank all of those who sent flowers, cards, well-wishes, and prayers during this difficult time. It brought our grandmother and us great comfort,” Mr. Obama said in the statement. “Our grandmother was a private woman, and we will respect her wish for a small private ceremony to be held at a later date.”