It sure didn’t feel like January in the Northeast over the past few days. At the time of year when the days are near their shortest and the weather should be near its coldest, temperatures across the region warmed to the high 60s and low 70s — 30 to 35 degrees above average. Records for daily highs were broken from Columbus, Ohio, and Pittsburgh to New York City and Bangor, Maine. Many residents took the warm spell as a belated holiday gift and went outside to cycle or jog or picnic with friends and family as if it were spring.

Some of the readings were especially eye-popping: Highs of 70 were seen in Boston on consecutive January days for the first time since record-keeping began in 1872. Buffalo, where the temperature on the same date last year never went above 20, reached 67 on Saturday. Charleston, W.Va., hit 80 degrees. It couldn’t last, of course: A cold front moving in late Sunday was expected to reset the region’s weather much closer to the seasonal range. But what was that anomalous warm spell all about? Here’s what the experts say.

Was it the fabled ‘January thaw’?

January is when the annual weather cycle reaches bottom in North America, with the coldest average temperatures expected around Jan. 23 — about a month after the shortest day of the year, the winter solstice. But people have long noticed and remarked on the tendency, especially in the Midwest and the Northeast, to have brief warm spells around that time, an event popularly known as a January thaw.