An elementary school teacher identified as Jamie Buckley, arrived on work shortly before 7.30am on Tuesday in Panama, parked her vehicle and then forget the toddler was there.
After parking the vehicle Jamie went to Cedar Grove School to teach, The Independent reported.
She found her daughter dead after left work at around 3.15 pm.
"Investigators from the criminal investigations division and the crime scene unit were called to the scene," said a statement posted by the Bay County Sheriff's Department.
On Tuesday afternoon, temperatures in Panama City reached 83 degrees, according to data from Weather Underground. Once outside temperatures reach 80 to 100 degrees, temperatures inside a car can climb up to 131 to 172 degrees, according to a 1998 case study from the Centres for Disease Control and Prevention.
At least 30 children died in hot cars in the US last year, said media report.