Most of the four-state area will be under a heat advisory today, while some areas will be under an excessive heat warning.

According to the National Weather Service, temperatures are expected to break 100 in many areas. Coffeyville will see a high of 102 and a heat index of 105.  A heat advisory starts at 1 p.m. for Woodson, Allen, Wilson, Neosho, Montgomery and Labette Counties.  Washington, Nowata and Craig counties in northeast Oklahoma including areas east and south will be under an excessive heat warning starting at noon due to higher humidity levels pushing up the heat index.