Across much of the world, hotter days are no longer arriving alone. The air itself is changing, sometimes turning from dry oven to steam bath, other times drying out even as thermometers climb. As ...

Some hot days feel even worse thanks to high humidity, trapped heat and dew points. Cities are especially vulnerable. By Nazaneen Ghaffar Nazaneen Ghaffar is a reporter on The Times’s weather team. It ...