If you live in Florida or Ohio, earthquake insurance probably is not crucial. But experts strongly suggest this type of coverage for those who live in earthquake-prone areas.

Wilson says costs for this type of coverage "depend entirely on where you are, home construction and value."

An average home in what's considered a fairly high-risk area could be several hundred dollars (more in California).

The cost of earthquake coverage varies and is likely to be more expensive in areas at particularly high risk for such natural disasters.

"It's typically more than flood insurance relative to the risk because it isn't subsidized," says Wilson.

Despite the importance of such coverage, Hungelmann estimates that only 20 percent of people who live in earthquake-prone areas actually have earthquake coverage.

"Don't wait until the last possible moment," Hungelmann says.