After the seesaw temperatures that have defined 2026 so far, spring — which begins on Friday — could be buggy. Summer could be, too.

As the U.S. flu season winds down, health officials say the flu vaccine didn’t work very well, with one of its worst effectiveness rates in more than a decade. A new strain that dominated the early ...

Winter has brought California's Sierra Nevada a below-average amount of snow, and the snowpack has been shrinking for weeks.

Avian influenza detections in birds have started to decline across Europe following an autumn and winter during which circulation of the virus in waterfowl reached its highest level in five years, ...