What was once unthinkable has now happened two years in a row: 70-degree temperatures have hit the U.S. Northeast in the depths of February.

New York and Boston hit 70 degrees on Tuesday, a daily record. On Wednesday, New York, Philadelphia and Washington, D.C., all set records with highs of 78, 77 and 79, respectively.

“Really crazy — and just like last year,” said Matt Rogers, president of the Commodity Weather Group. “We might get a March colder than February nationally.”

One year ago, a warm front pushed temperatures into the 70s, sparking tornadoes in Massachusetts — a first — and sending natural gas prices tumbling as people opened windows rather than cranked thermostats. For New York, Boston and Washington, February was actually warmer than March.

“It is pretty comparable to the warm-up we saw last year; even the dates are pretty similar as well,” said Marc Chenard, a senior branch forecaster at the U.S. Weather Prediction Center in College Park, Md. “It is definitely comparable.”

Much of the eastern U.S. has been about 20 degrees above normal this week, according to the National Centers for Environmental Information.

But it’s not hot everywhere. Weather has been see-sawing nationwide, with freeze warnings posted for large swaths of California, the National Weather Service said.

This doesn’t mean February is going to be transferred from winter to spring.

“There is still a polar night: no sun inside the polar circle, and so it gets cold,” said Kevin Trenberth, distinguished senior scientist at the National Center for Atmospheric Research in Boulder, Colo. “But in the lower latitudes it is warmer, and the oceans are warmer.”

Sea surface temperatures are above 70 degrees off the coast of North Carolina, according to the National Data Buoy Center in Stennis Space Center, Miss. The warm ocean has added to winter’s volatility.