Economists had estimated a reading of 86.5 for September, up from 85.7 last month.
Richard Curtin, chief economist of the survey, wrote: "The decline in optimism continued to narrow in late September as consumers increasingly concluded that the stock market declines had more to do with international conditions than the domestic economy."
Curtin added, "The true significance of these findings is not the diminished economic prospects, but that consumers now believe that global economic trends can directly influence their own job and wage prospects as well as indirectly via financial markets."
For now, consumers think this influence is muted.