The average number of tornadoes in each state between 2005 and 2014.
A state-by-state look at how spring is coming earlier, on average, in a warming world.
Spring has been getting steadily warmer almost everywhere. Nationwide, temperatures have climbed an average of 1.9°F since 1970 (0.42°F per decade).
Average precipitation during meteorological spring hasn't changed much since 1970. But regional patterns tell a different story.
Record highs across the U.S. this winter have markedly beat the number of record lows by a margin of 3 to 2.
Global warming does not happen uniformly across every region, nor across every season.
See when winter brings the coldest day of the year for different parts of the U.S.
Take a look at how winters have been warming across the continental U.S. from 1970 to 2013.