Another heat wave is about to hit the Southland, with temperatures expected to soar up to 18 degrees above normal in Los Angeles County between Monday morning and Thursday evening, forecasters said Friday.

The expected high heat will result from very strong high pressure, along with warm offshore winds from the north, which are rare for this time of the year, said National Weather Service meteorologist Curt Kaplan.

The heat will heighten wildfire concerns, he said.

Kaplan said Thursday’s high is expected to be around 108 degrees in Woodland Hills, which would be 18 degrees above normal. The normal high in Downtown L.A. for this time of the year is 84 degrees, but next week’s Downtown highs are expected to be in the mid 90s, he said.

Adding to what is likely to be widespread misery, the nights will not cool down all that much. Nighttime temperatures are expected to be in the mid 70s Downtown and in the valleys, and the low 80s in the deserts, Kaplan said.

An NWS statement warned that the expected temperatures create an “increased potential for serious heat-related illnesses, especially for the young and elderly, those performing outdoor activities, as well as those without access to air conditioning.”

There also will be an “increased potential for power outages.”

The NWS forecast temperatures in the low- to mid-80s through Sunday before rising Monday morning.  Highs next week in Long Beach are forecast to be in the upper-80s.