It's already been a very record-breaking hot year

It's been so warm in the United States this year, especially in March, that national records weren't just broken, they were deep-fried.

Temperatures in the lower 48 states were 8.6 degrees above normal for March and 6 degrees higher than average for the first three months of the year, according to calculations by the National Oceanic and Atmospheric Administration. That far exceeds the old records.

The magnitude of how unusual the year has been in the U.S. has alarmed some meteorologists who have warned about global warming. One climate scientist said it's the weather equivalent of a baseball player on steroids, with old records obliterated.

"Everybody has this uneasy feeling. This is weird. This is not good," said Jerry Meehl, a climate scientist who specializes in extreme weather at the National Center for Atmospheric Research in Boulder, Colo. "It's a guilty pleasure. You're out enjoying this nice March weather, but you know it's not a good thing."