photo by: National Weather Service

A temperature and humidity forecast from the National Weather Service through Friday night.

High temperatures in Douglas County will remain in the 100s through Friday, but cooler weather is expected over the weekend.

The National Weather Service in Topeka extended its heat advisory through Friday after it was expected to end Thursday afternoon, meteorologist Sarah Teefey said.

“We still have very hot and dry patterns persisting here this week and temperatures for Friday have been nudging up a little bit each day in the forecast. In and around Douglas County we have temperatures between 100 and 103 degrees for Friday afternoon,” Teefey said.

The heat index is expected to be even higher at 106 degrees on Friday, she said. The heat index factors in the amount of moisture in the air that more accurately reflects how hot it actually feels.

The heat wave began Saturday, and the Lawrence area has experienced high temperatures at or exceeding 100 degrees all week. The last time that a heat wave has lasted this long was in 2011, when the area experienced 10 consecutive days with temperatures at or exceeding 100 degrees, Teefey said.

The heat is expected to subside by Saturday with a high near 91 and fall even lower on Sunday with a high near 80, Teefey said. Normal weather conditions are expected throughout September with just a slight chance for above-average temperatures, she said.

In addition to falling temperatures, there is a slight chance for rain overnight on Friday into Saturday morning, Teefey said.