All regions of the continental U.S. have seen the frost-free season, defined as the stretch between the last below-32°F reading in the spring and the first in the fall, grow longer.
Better grab your calamine lotion. More CO2 means bigger poison ivy plants.
Climate change has increased pollen counts and the length of the pollen season, trends that are expected to continue through mid-century.
Spring is arriving earlier across the U.S. by an average of three days.
Foliage color and timing has been starting later, on average, in a warming world.
Scientists say increased CO2 emissions are making poison ivy worse.
The highlights of NOAA's 2013 Spring climate summary.
If it seems like autumn leaves are taking longer to change color, you're not imagining things. Over the past 25 years, the onset of autumn has shifted.