High ocean temperatures fueling Hurricane Idalia as Florida braces for landfall

The hurricane could strengthen to category 3 by the time it hits the state's coast, with a storm surge of up to 12ft

• Follow live updates on Hurricane Idalia here

Hurricane Idalia, which has triggered evacuations as it threatens to pummel the northern reaches of Florida, is being fueled by unusually high temperatures in the Gulf of Mexico, part of a trend of extreme marine heat that has dominated the summer.

Idalia has churned across the Gulf of Mexico as a category 1 storm but is expected to strengthen to a category 3 event by the time it crunches into Florida's western coast on Wednesday, making it the first hurricane to hit the US this year.