Months after the end of the El Nino weather phenomenon, a colder condition called La Nina has replaced it.
The National Weather Service reports that La Nina caused temperatures to drop to a bone-chilling minus 74 degrees Fahrenheit in interior Alaska in late January and early February.
La Nina is also the cause of flooding and heavy snow in other parts of the West and extreme weather from South America to Asia.
After more than a year of disrupting weather around the world, El Nino caused an unusual warming of the water in the eastern Pacific Ocean, which eased last May.
But rather than returning to normal, readings showed the ocean cooled sharply into a condition known as La Nina, the opposite of El Nino. El Nino is Spanish for "little boy." La Nina means "little girl."
"This La Nina provides the physical link between many of the unusual weather patterns seen recently in far-flung parts of the globe," said John Janowiak, Weather Service scientist.
"While parts of Alaska have experienced severe cold, most of the lower 48 states, especially those in the southern tier, have enjoyed record-breaking warm temperatures," Janowiak added.
La Nina contributed to a series of huge storms that blasted Washington, Oregon and northern California with hurricane-force winds, heavy rains and mountain snows, he said.
As a result, many sections of northern-tier states in the West have experienced precipitation totals that are in the top 10 of this century.
On the other hand, parts of the Southwest suffer from lack of precipitation.
Elsewhere in the world, La Nina's impacts include heavy rains, severe storms and flooding in southern Africa, drought in Kenya and Tanzania, flooding in the Philippines and Indonesia and abnormal wetness in northern South America.
The same regions suffered the opposite effects during the 1997-98 El Nino.
Not the fault of La Nina, however, are the current bitter winter storms in Europe, where heavy snow has disrupted travel and avalanches have claimed several lives.
Scientists at the Weather Service's Climate Prediction Center in Camp Springs, Md., say this La Nina has grown into one of the strongest such episodes of the past 50 years.