Heatwave expected to spread to 250m Americans in midwest and north-east

Scorching temperatures have already swept south-east where Florida is now grappling with severe flooding

The scorching heatwave that has swept the US south-east in recent weeks will soon spread to the country's midwest and north-east regions, affecting nearly 250 million Americans.

Temperatures are stuck at 90F (32C) or above for at least the next week in much of the US, the National Weather Service (NWS) predicted. The NWS defines a heatwave as a period of temperatures exceeding 90F for two or more days, and this one could last until 26 June.