Wednesday is slated to be the hottest day of the week as Santa Ana conditions continue across San Diego County, the National Weather Service said.

Temperatures will increase as much as 15 to 20 degrees above average for portions of the valleys and inland coastal areas, the NWS said.

A heat advisory will be in effect until 7 p.m. for our Valleys.

Santa Ana conditions will subside on Thursday, but it will still be hot. By Friday, Halloween, our onshore flow will start to develop again, cooling us down, NBC 7's Meteorologist Sheena Parveen said.

Halloween will be comfortable with cooler daytime highs and pleasant evening temperatures for trick-or-treaters.

Wednesday temperatures:

Coast: sunny - mid 80s

Inland: sunny – mid 90s

Mountains: sunny, breezy - near 80

Deserts: sunny – low

See Full Page