Three humidity-adjusted heat numbers dominate the summer forecast, and they answer different questions. The one everybody quotes assumes you are standing in the shade.

A central AC running flat out at 79 degrees on a 99-degree afternoon is usually doing exactly what it was engineered to do. The symptom that actually signals a fault is different, and easy to miss.

Closing vents in unused rooms feels like it should cut your bill. The physics of your ductwork says otherwise, and the habit can quietly damage your HVAC system.

A heat dome is the stalled high-pressure lid behind record-breaking heat waves. Here is how it forms, why humidity makes it deadly, and how long it lasts.

Shelters are filling and the ports are shut as a Category 5-equivalent storm bears down on Guam and the Northern Mariana Islands, with landfall due Monday.

More than 165 million Americans face major or extreme heat risk this week as a record-threatening heat dome settles over the East Coast and Midwest through the July Fourth weekend — and complicates World Cup matches.

Rain ran nearly 40% below normal for the month, with no low-pressure systems forming and El Nino building, before the monsoon finally turned toward Delhi.

Six to seven inches of rain in hours killed at least four people and forced dozens of water rescues across central Kentucky.

A record-breaking heat dome that has killed dozens in Western Europe is sliding east, with Germany and Poland bracing for the weekend peak.

A heat-stressed transformer failure in Brittany cut power to tens of thousands of homes as France logged its hottest day on record and Europe's heatwave spread north.

Forty people have drowned trying to cool off, two small children died in a hot car, and France just recorded its warmest night on record. The heat is now a body count, not a forecast.

A solstice-week heat dome pushed France toward a national record and shut hundreds of schools, with Britain's peak still days away.

Spain braces for 44C, France curbs festival drinking and Britain faces its hottest June day on record as the heat builds toward a Monday peak.

A heat dome has settled over Western Europe for the summer solstice, with France warning Monday could be its hottest day on record and 53 departments already under an orange alert.

The system may or may not earn a name. The flooding threat from the Texas coast into the Deep South is already here, the hurricane center says.

With a disturbance brewing in the Gulf and rain already falling, Texas shifted its emergency operation to round-the-clock footing ahead of the worst of the week.

The famous claim that returning wolves healed Yellowstone from the top down rests on a 1,500% willow figure that a new analysis calls a modeling artifact.

The EPA transmitted four California vehicle and equipment emission waivers to Congress on Friday, arguing they qualify for fast-track repeal under the Congressional Review Act.

A patch of ocean south of Greenland keeps cooling while the planet warms. New observational work says the explanation runs deep, and so do the stakes.

The Pacific has flipped into its warm phase, and the agency’s new measuring stick says this one could be big. Here is what an El Niño winter usually brings.