The average rate for a 30-year fixed-rate mortgage fell to 4.23% in the week that ended Feb. 6, hitting the lowest level since November, from 4.32% in the prior week, according to a Thursday report from federally controlled mortgage buyer Freddie Mac/quotes/zigman/226335/delayed/quotes/nls/fmccFMCC-1.69%. A year ago, the 30-year rate was at 3.53%. “Mortgage rates fell further this week following the release of weaker housing data,” said Frank Nothaft, Freddie’s chief economist, citing a recent drop in a gauge of upcoming home sales, among other reports. The average rate for the 15-year fixed-rate mortgage declined to 3.33% in the latest week from 3.40% in the prior week. Meanwhile, the rate for a 5-year Treasury-indexed hybrid adjustable-rate mortgage fell to 3.08% from 3.12%. The rate for a 1-year Treasury-indexed ARM fell to 2.51% from 2.55%.