Factbox-From heat wave to thunderstorms, third of US to see extreme weather

Tennis ball-sized hail pounds Italy injuring more than 100 people

Wildfires slowly abate in Greece but temperatures rise

Explainer-How El Nino is helping drive heatwaves and extreme weather

Record heat: Stocks winners and losers

Factbox-From Hawaii to Kentucky, a mix of severe weather

Sao Tome and Principe country profile

Colombia landslide: Rescuers search for survivors amid mud

Wildfires in Greece raze forests, spur evacuations; allies send aid

Record heat wave grips China as flood toll rises in South Korea

U.S. hit by blazing heat, smoky air, tropical storm all at once

What Is El Niño, and Why Does It Have Such a Big Impact?