For the first time in 20 years, the U.S. is on track to set more record lows than record highs in 2013.
This season was the least active since 1982 and the sixth-quietest since 1950.
Foliage color and timing has been starting later, on average, in a warming world.
As the graphic shows, people cause most wildfires. But lightning-ignited fires burn by far the most territory.
Record highs have outpaced record lows by a bigger margin each decade since the 1960s.
The highlights of NOAA's 2013 Spring climate summary.
The number of big fires has shot up since 1970, with the largest number occurring during the years with the highest temperatures.
By 2100, sea level may be as high as six-and-a-half feet above 1992 levels, putting the homes of 7.8 million Americans at risk of being flooded.