The National Weather Service has issued an excessive heat warning for the greater Seattle area, including Mercer Island, as well as a red flag warning for fire danger.

The excessive heat watch begins Thursday afternoon and runs through Friday evening. Temperatures both days are expected to hit the 90s, with a high of 91 expected for Thursday and up to 94 degrees on Friday. Night time lows are only expected to drop to just below 70s for a couple of hours.

Temperatures are expected to cool back down, relatively, to a high of 81 on Saturday and 78 on Sunday.

Due to the high temperatures, and the potential for high humidity, residents are encouraged to stay hydrated by drinking lots of fluids, and to stay inside or in air-conditioned areas when possible.

The red flag warning, only the second issued in the last decade means the area is at a high risk for fires. The warning goes into effect at 1 p.m. Wednesday until 9 p.m. Wednesday night, for the combination of northern winds and low humidity.

The most concerned areas included the I-5 corridor through King, Pierce, Thurston and Lewis counties. Winds are expected to range from 8 to 14 miles per hour, with gusts up to 20 mph. The big concern is that any fire started during this time period could quickly spread out of control.

Learn more on the National Weather Service’s website.