Other superpowers didn't fare better than Northern Europe either.

Germany came in 16th place for the second year, while the United Kingdom moved up four spots to 19th place and Russia moved up seven spots to 49th place. Japan moved up two spots to 51st place, while China moved up four spots to 79th place.

People in the Central African Republic are unhappiest with their lives, according to the survey of 155 countries, followed by Burundi (154), Tanzania (153), Syria (152) and Rwanda (151).

Happiness is many things

Happiness isn't just about money, although it's part of it.

Real gross domestic product per capita is one of the key measurements, said the report.

Others include generosity, a healthy life expectancy, having someone to count on, perceived freedom to make life choices and freedom from corruption, the report's authors argued.

They said it's a better measure of human welfare than analyzing education, good government, health, income and poverty separately.

"The World Happiness Report continues to draw global attention around the need to create sound policy for what matters most to people -- their well-being," said Jeffrey Sachs, the report's co-editor and director of the Earth Institute at Columbia University, in a statement.

"As demonstrated by many countries, this report gives evidence that happiness is a result of creating strong social foundations. It's time to build social trust and healthy lives, not guns or walls. Let's hold our leaders to this fact."

Not just about the money

Norway rose to the top of the rankings despite declines in oil prices, demonstrating that what countries do with their money -- not just the increase in finances -- matters.

"It's a remarkable case in point," said report co-editor John Helliwell of the University of British Columbia.

"By choosing to produce oil deliberately and investing the proceeds for the benefit of future generations, Norway has protected itself from the volatile ups and downs of many other oil-rich economies."

"This emphasis on the future over the present is made easier by high levels of mutual trust, shared purpose, generosity and good governance," added Helliwell, who is also co-director of the Canadian Institute for Advanced Research.

"All of these are found in Norway, as well as in the other top countries."

Happiness at work

This year's report also focused on happiness in the workplace.

"People tend to spend the majority of their lives working, so it is important to understand the role that employment and unemployment play in shaping happiness," said Jan-Emmanuel De Neve, a professor at the University of Oxford's Saïd Business School.

"The research reveals that happiness differs considerably across employment status, job type, and industry sectors."

De Neve, who co-authored the report's chapter on happiness at work, added that people in well-paid roles are happier, but money is only one predictive measure of happiness.

"Work-life balance, job variety and the level of autonomy are other significant drivers," said De Neve.

"There is a clear distinction in happiness between white and blue collar jobs with managers or professionals evaluating the quality of their lives at a much higher level than those in manual labor jobs even controlling for any possible confounding factors."

The report focused on other factors affecting happiness.

"In rich countries the biggest single cause of misery is mental illness," said Professor Richard Layard, director of the Wellbeing Programme at the London School of Economics' Centre for Economic Performance.

The birth of 'Gross National Happiness'

Credit goes to the tiny country of Bhutan for shining a light on happiness. Its prime minister first proposed a World Happiness Day to the United Nations in 2011 and launched an international focus on happiness.

The first of five World Happiness Reports was first published in April 2012 in conjunction with the U.N. High Level Meeting on happiness and well-being. Since 2012, many governments and governmental organizations have made well-being or happiness a priority.

In February, the United Arab Emirates held a full-day World Happiness meeting. There was World Happiness Summit in Miami on March 17-19, while Erasmus University in Rotterdam is hosting three-day meeting on happiness research and policy starting Monday.