TULSA, Okla. (AP) - The National Weather Service has issued a heat advisory for much of eastern Oklahoma, warning of unseasonably hot temperatures.

Forecasters say a heat index of 105 to 110 degrees is expected Monday afternoon as a strong ridge of high pressure settles into the state. The heat advisory is in effect from 1 p.m. to 9 p.m. Monday in areas including Tulsa, Muskogee, Bartlesville and McAlester.

In Oklahoma City, an ozone alert is in place. Forecasters warn that people with heart or respiratory problems should limit their physical exertion and outdoor activities because of high concentrations of ozone.

Forecasters say hot, humid weather is predicted throughout the week.

(Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)