All but the northwestern corner of Arkansas was set to go under a heat advisory Monday morning, and forecasters warned afternoon temperatures may reach hazardous levels for the rest of the week.
Air temperatures are expected to reach the 90s for most of central and southern Arkansas Monday, and the heat index will eclipse 105 degrees, according to the National Weather Service. In the Delta, the heat index could approach 110 degrees.
The heat index accounts for heat and humidity to measure how hot the air feels. Heat advisories are issued when it reaches 105 degrees.
The weather service said heat-advisory temperatures were likely in the afternoons throughout this week. A statement issued Monday advised people to stay inside or hydrate when working outside.
In addition to sweltering temperatures, the weather service said isolated thunderstorms with cloud-to-ground lightning were possible Tuesday.