This extreme weather event will cause temperatures to soar in highly populated cities, potentially fouling air quality and exacerbating human health conditions.
Saturday's looking close to perfect. Sunday won't be too shabby, either.
The day started pleasant. Then the thunderstorms rolled in.
The Atlantic hurricane season has been unusually quiet so far this season, but the tropics have finally started to wake up this week.
But September is still likely to bring some hot days.
Once we get through today's raindrops, good times are ahead.
Humidity begins to drop tonight and tomorrow, despite rain also falling at times.
Europe will see its third major heat event this year, with temperatures 15 to 20 degrees above normal.
Fires in the Amazon rainforest show up clearly and ominously in satellite imagery, showing the increased deforestation trends that are putting the planet's carbon savings account and bastion of biodiversity at risk.
The humidity has increased 5 to 10 percent just since 1970, turning hot summer days even more unbearable.
The storm displayed ominous clouds, lightning, a rainbow and, in its wake, a large display of mammatus clouds at sunset.
Amazon wildfires have spiked, sparking fears of land grabs for agriculture and the release of greenhouse gases that will accelerate global warming.
This summer, Alaska has faced extreme heat, irregular rains and wildfires.
Scientists hope this machine-learning technology could unlock the secrets behind large hail formation.
The weekend is comfortably dry.
Thursday should present our last 90-degree day for a while.
It's the third-highest total on record to date, and already two weeks past the average number of 90-degree days for a full year.
A destructive storm propelled baseball-sized hail at 70 mph as it ravaged a Montana wildlife management area.
In just 15 minutes, a small mass of clouds quadrupled in size, shot 40,000 feet high and morphed into a raging thunderstorm.
Not quite as hot over the next few days, but the chances for daily showers and thunderstorms remain elevated through Friday.
Storms tomorrow should be less numerous than today.