• D.C.
  • BXL
  • Lagos
  • Riyadh
  • Beijing
  • SG
  • D.C.
  • BXL
  • Lagos
Semafor Logo
  • Riyadh
  • Beijing
  • SG


Flagship newsletter icon
From Semafor Flagship
In your inbox, every weekday
Sign up

US heat dome worsens

Jul 29, 2025, 6:22am EDT
PostEmailWhatsapp
A photo of a heatwave in Chicago
Audrey Richardson/Reuters

A searing heat dome in the US left more than 150 million people facing dangerous temperatures yesterday, and today could be hotter still.

Tampa Bay broke 100°F (37.7°C) for the first time in 130 years of records on Monday, notable because Florida’s humidity usually keeps thermometer temperatures somewhat lower, Scientific American noted, since heating water takes lots of energy.

The US has so far experienced one of the 10 hottest summers on record, and while temperatures may be about to break — a cold front should bring a 20°F (11°C) change from Wednesday — that may cause new problems: Rapid coolings can lead to heavy rain and flash flooding, which the US has already seen plenty of this summer.

AD