You can't put a price on the weather, but Xcel Energy Inc. executives determined that it's responsible for most of the company's profit growth last year.

Minnesota's largest utility said Thursday that its profit grew 7 percent, or 13 cents a share, in 2013 and much of that came from the effect that extreme weather conditions had on energy demand. Weather contributed earnings of 11 cents a share, Xcel said.

Minnesota was hit by an extended winter, with parts of the state even experiencing a snowstorm in May. The state, along with others that Xcel serves like Colorado and Texas, also experienced a hotter-than-usual summer that drove demand for air conditioning.

In a discussion with analysts, Xcel executives said the weather-related effect on its financial performance was outsized and unlikely to soon be repeated. "You can't count on 11 cents, that's for sure," Xcel Chairman Ben Fowke said.

Xcel operates in so many states that a convergence of extreme weather ­conditions is rare. Just this month, Xcel's largest market, Minnesota, experienced extreme cold while its second-largest market, Colorado, had mild weather.

When an analyst asked whether Xcel would adjust its first-quarter outlook upward because of Minnesota's cold January, Teresa Madden, Xcel's chief financial officer, suggested that Colorado might be an offset. "It's so early, and things can change with weather," she said.

Xcel's financial outlook assumes that weather conditions will follow a historical average, though the company routinely tracks deviations from that pattern.

In 2013, the company's measurement of heating degree days, those days when temperatures are colder than normal and drive up heating demand, was 8 percent greater than the historical average and 15 percent greater than in 2012.

Meanwhile, last summer was even more extreme in Xcel's service region, with cooling degree days 25 percent greater than normal. But the 2013 summer had 13 percent fewer cooling degree days than 2012, when drought gripped much of the country.

For the last three months of 2013, Xcel earned $150.1 million, or 30 cents a share, which was above analysts' forecasts of 29 cents a share. Revenue was $2.73 billion, slightly below the $2.74 billion forecast.

In the 2012 fourth quarter, Xcel had net income of $140.2 million, or 29 cents a share, on revenue of $2.55 billion.

But executives for several months have been forecasting slower earnings growth for 2014, leaving investors to keep an eye on the Xcel's dividend plans.

On Thursday, the company reaffirmed its forecast for 2014 earnings of $1.90 to $2.05 a share, only slightly higher than the $1.95 a share it earned for full-year 2013. Meanwhile, the company said it expects to deliver dividend increases of 4 to 6 percent this year and for several years ahead.

Xcel shares closed Thursday up 2 percent, or 57 cents, to $28.73.