Just as Americans were getting ready for the Thanksgiving holiday, mortgage rates fell again, reaching record lows in Bankrate.com’s weekly national survey and dropping to the lowest level in Zillow’s Mortgage Rate Monitor since its inception 18 months ago.

The average conforming 30-year fixed mortgage rate fell to 5.00 percent, according to Bankrate.com. The average 30-year fixed mortgage has an average of 0.44 discount and origination points. On Zillow, the weekly average rate borrowers were quoted for 30-year fixed mortgages decreased six basis points last week to 4.69 percent, down from 4.75 percent the week prior

Rates for 15-year fixed mortgages fell two basis points to 4.23 percent from 4.25 percent, and 5-1 adjustable rate mortgages increased one basis point to 3.69 percent, from 3.68 percent the week prior on the Zillow monitor. Bankrate had the average 15-year fixed mortgage down to 4.47 percent while the larger jumbo 30-year fixed rate rose to 6.03 percent. Adjustable rate mortgages decreased slightly this week, with the average 1-year ARM inching down to 5.37 percent and the 5-year ARM slipping to 4.54 percent.