The second day of a heat wave is expected to send temperatures soaring into the triple digits Tuesday in San Diego County.
National Weather Service forecasters have issued an excessive heat warning in the county that began at 10 a.m. Monday and ends today at 8 p.m., with extreme heat expected everywhere but the immediate coastal areas.
High temperatures near the coast will be in the low 80s today, while temperatures were expected to reach into the high 90s today in the western valleys and the 100s in Ramona and Alpine, forecasters said.
A high of around 111 degrees is expected in Borrego Springs.
The heat was expected to fall slightly Wednesday, when monsoonal moisture was expected to return to the region.
RELATED: Heat Wave To Descend On San Diego Again This Week
South swells from Tropical Storm John were expected to create high surf conditions peaking Thursday afternoon through Saturday, according to the NWS.
The weather service and law enforcement caution that those who work outdoors should avoid the midday sun, wear light, loose-fitting clothing and drink plenty of water.
Nighttime lows will be in the mid 80s today in the county deserts, meaning the minimal cooling at night could pose a health risk to those who don't have access to air conditioning because the body needs time to cool down from the day's heat, according to the NWS.
Avoid leaving senior citizens and kids at home without air conditioning, if possible. And never leave a child, senior or pet in a parked vehicle, even with windows cracked open, because interior temperatures can quickly turn lethal.