This is the first time North Korea has attempted a rocket launch in winter, and experts say the timing of preparations and the launch itself will depend heavily on weather conditions.

"Pyongyang's announcement of a twelve-day launch window, over twice as long as the five-day window for the April 2012 test, may have been based on careful consideration of possible delays or technical problems due to winter weather," 38 North says.

Previous launch attempts by the North in 2006 and 2009 also failed to achieve their stated goal of putting a satellite in orbit and provoked international condemnation.