After five consecutive monthly declines, the index rose in July. But confidence returned to its downward trend in August, despite gains in stock markets.
But the index that assigns 1985 a base value of 100, rose in September from 71.1 to 83.7, the Conference Board said.
The monthly Consumer Confidence Index is based on a survey of 5,000 households.
"Despite continuing economic uncertainty, consumers are slightly more optimistic than they have been in several months," said Lynn Franco, director of the board's Consumer Research Center.
In the September survey, respondents indicating business conditions are "good" rose from 15.3 percent to 15.5 percent. Respondents indicating conditions declined were fell from 34.3 to 33.3.
Respondents indicating jobs were easy to find rose from 7.2 percent to 8.3 percent, while those who indicated jobs were hard to find fell from 40.6 percent to 39.9 percent.