Maine’s weather came in like a lion in 2015 – with the coldest February on record – and went out like a lamb, with a balmy December that set a record in Portland and was on track to be the warmest ever statewide.

“We started on a very cold note, and ended on a very warm one,” said meteorologist John Cannon, of the National Weather Service in Gray.

Final statewide figures for December temperatures weren’t available late Thursday, but it’s “likely the warmest” December on record for the state, Cannon said.

There’s no question Portland broke the record for the warmest December, he said.

With just hours to go before the new year, Portland’s average temperature in December was 38 degrees, he said. That’s 9 degrees above the average and breaks the previous record average of 34.8 degrees set in December in 2001.

“That shatters the record,” Cannon said.

December has been marked by unusual weather around the globe, ending a year of record-setting weather, with July being the hottest month ever measured and 2015 set to be the warmest year on record.

It is also the year negotiators from nearly 200 countries reached a first-of-its-kind agreement in Paris on curbing greenhouse gas emissions in a bid to rein in man-made climate change.

In recent days, a storm that started out by causing deadly floods and tornadoes in the continental United States carried warm air far north, sending temperatures soaring 50 degrees above normal in the Arctic and leaving the North Pole warmer than Chicago.

From Illinois to Texas, 6 to 12 inches of rain have fallen since Dec. 26. Dozens of new precipitation marks were set last weekend, in some cases doubling or even tripling old records.

“Major to historic” river flooding is predicted in St. Louis through Sunday, according to the weather service. The Mississippi River, which cuts through the heart of the city, is expected to hit 13 feet above flood stage – one of the top three crests on record. Officials in Illinois and Missouri had blamed 20 deaths on the flooding through Thursday.

And after river levels drop, the Mississippi’s floodwaters will continue to move downstream through mid-January, meeting runoff from excessive rain in the Southeast. Memphis, Vicksburg, Mississippi, and Baton Rouge, Louisiana, all are braced for significant flooding.

And in California, which is in the midst of its worst drought in a century, the Sierra Nevada snowpack – which makes up a third of the state’s water supply – is at 145 percent of normal.

The same giant El Niño pattern in the Pacific Ocean that fueled wet weather in California is causing downpours in South America, swamping regions of Paraguay, Argentina, Brazil and Uruguay. Storms in England, Scotland and Northern Ireland have made it the wettest December in some locations of the United Kingdom.

December’s warm temperatures have broken records across the Northeast, according to preliminary month-end numbers from the weather service.

The average temperature in Boston was 45.4 degrees, or nearly 11 degrees above normal, according to numbers through Wednesday. The previous warmest December on record was 2006, when the average was 41 degrees. The average temperature in New York City’s Central Park was 51, or 13.3 degrees higher than normal for the month, and Burlington, Vermont, is running about 6 degrees above the old record for the average temperature for the month.

Concord, New Hampshire, bested a record of 35.4 degrees that had stood since 1891. In Providence, Rhode Island, the temperature reached 50 degrees on 21 December days, shattering the previous record of 13 days.

“A few days of 50-degree weather in December is not unusual, what was so unusual this year is that it was such a prolonged pattern of warmer weather,” said Bill Simpson, a weather service meteorologist in Taunton, Massachusetts.

Cannon said Maine had its second-latest date of first snowfall, Dec. 30, compared to the latest first date of snow of Jan. 16 in 2000.

The year’s snowfall, despite the string of snowstorms last winter, isn’t on track to even crack the top 10 snowiest years, Cannon said.

The Associated Press and The Washington Post contributed to this report.