Mortgage rates have dipped and are now very close to a new all-time low in a popular weekly survey that goes back nearly half a century.

Rates have fallen so far that U.S. homeowners altogether could save a mind-blowing $61 billion a year by refinancing, according to a new estimate.

Do you want a piece of that? If you own a home and haven't refinanced recently, it's time to consider it — especially if you're looking to tighten your family budget in the midst of the coronavirus crisis.

Mortgage rates drop a couple of notches

Mortgage rates have slipped this week to an average 3.31% for 30-year fixed-rate loans, after two weeks stuck at 3.33%, mortgage titan Freddie Mac reports. Rates are very close to the record low of 3.29% hit last month in the Freddie Mac survey, which has been tracking mortgage rates since 1971.

The survey rates come with an average 0.7 point. Last year at this time, the typical rate on a 30-year fixed mortgage was almost one full percentage point higher, at 4.17%.

"Mortgage rates continue to hover near all-time lows for the third straight week. As a result, refinance activity remains high, but home purchase demand is weak due to economic tightening," says Sam Khater, Freddie Mac’s chief economist.

Freddie Mac predicts that the benchmark mortgage rate will average a low 3.3% throughout this year, way down from last year's 3.9%.

But finding the best mortgage rates available today takes a little bit of work, says Matthew Graham, chief operating officer of Mortgage News Daily. You've got to be prepared to shop around.

"The low 3% range is available for ideal scenarios, but two different lenders may be more than half a percentage point apart," Graham writes.

Low rates bring homeowners 'significant savings'

Mortgage rates have gone so low that the spread between today's rates and the average rate on outstanding mortgages is the widest since 2012, according to a new report from LendingTree.

In other words, homeowners are sitting on loads of loans that could use a refi.

"Borrowers who refinance stand to reap significant savings," says LendingTree's chief economist Tendayi Kapfidze.

He estimates that U.S. homeowners made $411 billion in mortgage payments last year. Refinancing their loans at today's super-cheap rates would bring the annual cost down to $350 billion — for a total savings of $61 billion a year.

Consumers who refinance mortgages taken out just one year ago, when rates were higher, are saving $60 a month for every $100,000 they borrow, Kapfidze says.

Despite the benefits, refinancing has been running hot and cold. Applications for refi loans jumped 10% last week, after falling 19% the previous week, the Mortgage Bankers Association says.

Other mortgage rates this week

Rates on other popular types of mortgage loans are mixed this week.

The average for a 15-year fixed-rate mortgage has risen to 2.80%, from 2.77% last week, Freddie Mac says. Fifteen-year loans are a popular refinancing option. They were averaging 3.62% one year ago.

Rates on 5/1 adjustable-rate mortgages have tumbled this week. The loans known as "ARMs" are fixed for five years and then can adjust up or down every year.

ARMs are currently being offered at an initial rate of 3.34%, down from 3.40% last week. At this time in 2019, the starter rates on those mortgages were at an average 3.78%.