For the 15th consecutive month, the Cost of Funds Index rose -- jumping more than 10 basis points during the latest month.
COFI ended August at 2.870%, according to the Federal Home Loan Bank of San Francisco, up from 2.757% in July. A year ago, the West Coast index was about a percent lower at 1.875%.
The 11th District FHLB reports the COFI average about 30 days following the end of each month.
The latest numbers were based on $552.0 billion average total funds, the FHLB said.
The 6-month LIBOR, which competes with COFI and the 1-year Treasury as the index for adjustable rate loans, was 4.2154% in September, according to Fannie Mae, up from 4.0817% in August.