The thermometer barely rose above zero last Jan. 5, as Gov. Mark Dayton was sworn in for his second term. It was a chilly start to a political year that never quite heated up for the governor.

Dayton ends 2015 with few of the banner legislative achievements that characterized his three previous years in office: a Vikings stadium deal, an income tax increase on the wealthy, funding for all-day kindergarten, a state minimum wage hike.

Following that string of successes, voters in 2014 rewarded the DFL governor with a second term — but also returned Republicans to the House majority. That left Dayton’s second term starting off like his first, with a legislative session that ended in a stalemate over the state budget.

At a news conference last week, Dayton said his second term was positive by his own favored yardstick.

“This has been a good year for Minnesota. That’s my measure,” Dayton said. He cited a strong state economy despite several pockets of concern, the 3.5 percent statewide unemployment rate, and a series of notices by national publications and groups that have trumpeted Minnesota’s quality of life and sound fiscal management.

And, unlike four years earlier, Dayton headed off a state government shutdown this year by striking a last-minute budget deal with Republicans. But it required him to retreat on what had been Nos. 1 and 2 on his wish list: full funding of all-day prekindergarten classes at public schools and a major infusion of new dollars into transportation infrastructure statewide via a gas tax increase.

Dayton also was unable to rally legislators for a special session last summer to help the struggling Lake Mille Lacs-area economy. Now he’s again trying to convince legislators of the need for a short special session in January to attend to several matters.

Starting his second (and he says final) term, Dayton proclaimed himself “Dayton Unbound” — cheekily hinting that lack of another election in his future meant a more unfettered style. But he learned the downside potential early on when he bluntly denounced a fellow DFL leader.

The February news conference during which Dayton proclaimed that Senate Majority Leader Tom Bakk had “stabbed me in the back,” said “I can’t trust him” and added that “he connives behind my back,” delivered the most riveting few minutes of the year in state politics. The public split between state government’s two most powerful DFLers reverberated well beyond the dispute over Cabinet pay raises that provoked it.

GOP House Speaker Kurt Daudt nimbly maneuvered the Dayton-Bakk schism while holding together the often-fractious House Republicans on budget votes. His skills will be doubly tested in 2016, as conservative donors and activists try to push Daudt further to the right.

On March 8, 201 legislators arrive in St. Paul — greeted by a $1.2 billion surplus to disperse, and with at least one eye on November, when every House and Senate seat is on the ballot.

Yet for Dayton, the window of time left to build on his first-term legacy will continue to shrink.