The National Weather Service was calling for Friday to be sunny and hot in the Baltimore area, with a high near 105 degrees and northwest winds at 6 miles per hour becoming southwest. Widespread haze was expected before noon. Heat index values will be as high as 119.

Friday night was expected to be partly cloudy, with a low around 86 and light and variable winds. There is a slight chance of showers and thunderstorms before midnight.

An excessive heat warning was in effect for Friday from 10 a.m. to 10 p.m. and for Saturday from 10 a.m. to 8 p.m. The combination of high temperatures and humidity may cause heat illnesses.

Baltimore City has opened its cooling centers Friday to provide free air conditioning and water for residents. In addition, residents can seek relief from the heat at any branch of the Enoch Pratt Free Library during normal business hours. Surrounding counties are directing residents to library branches and senior centers to get out of the heat.

In Baltimore City, five cooling centers will be open from 9 a.m. to 7 p. m. Friday and from 11 a.m. to 7 p.m. Saturday and Sunday. They are located:

5225 York Road

606 Cherry Hill Road (inside the shopping center on the second floor)

3939 Reisterstown Road

3411 Bank St.

1400 E. Federal St.

Six more cooling centers will be open from 9 a.m. to 7 p.m. Thursday and Friday only. They are located:

1000 Cathedral St.

1700 Gay St.

1601 Baker St.

2825 Fait Avenue

229 1/2 S. Eaton St.

4501 Reisterstown Road

Saturday was expected to be mostly sunny and hot, with a high near 103 degrees and west winds of 5 to 8 miles per hour. Heat index values will be as high as 113. The chance of thunderstorms is 30 percent.

Saturday night was expected to be mostly cloudy with a low around 81 degrees and west winds of 3 to 6 miles per hour. The chance of precipitation is 30 percent.