San Diegans will begin to feel an oncoming heat wave Thursday as temperatures rise by as much as eight degrees in part of the county.
The brunt of the heat wave is not expected until Friday when high pressure building over the country’s southwest region brings extreme temperatures to Southern California.
An excessive heat warning was issued by the National Weather Service for the foothills while a heat advisory is also in effect Friday for communities like Vista, Chula Vista, National City and San Diego.
During that period, San Diego’s coastal areas will likely see temperatures in the 90s and inland areas can expect temperatures breaking 100 degrees, NBC 7's Meteorologist Whitney Southwick said.
In those two days, elevated temperatures and high humidity can create dangerous situations where heat-related illnesses are common.
San Diego's valleys are expected to be between 102 and 107 degrees. Temperatures around the coast will be anywhere from 85-95 degrees and mountains will see temperatures up to 105 degrees.
The immediate coast and mountains above 6,000 feet will not experience the same extreme weather.
The Weather Channel says humidity in San Diego will be around 45 percent for those days.
According to the National Weather Service's heat watch map, potential heat risks are in the moderate to high range for most of San Diego County, while parts of Los Angeles rank as very high.
In order to prepare for the heat, the National Weather Service suggests residents drink plenty of water and stay in air-conditioned rooms when possible.
Avoiding prolonged sun exposure and checking in on neighbors and relatives are also advisable.