893
WWUS76 KSGX 190322
NPWSGX

URGENT - WEATHER MESSAGE
National Weather Service San Diego CA
822 PM PDT Mon Aug 18 2025

CAZ048-191130-
/O.CON.KSGX.XH.A.0002.250821T1700Z-250823T0300Z/
San Bernardino and Riverside County Valleys-The Inland Empire-
Including the cities of Moreno Valley, Rancho Cucamonga,
Riverside, Corona, Fontana, San Bernardino, and Ontario
822 PM PDT Mon Aug 18 2025

...EXTREME HEAT WATCH REMAINS IN EFFECT FROM THURSDAY MORNING
THROUGH FRIDAY EVENING...

* WHAT...Dangerously hot conditions with temperatures up to 106.

* WHERE...San Bernardino and Riverside County Valleys-The Inland
  Empire.

* WHEN...From Thursday morning through Friday evening.

* IMPACTS...Heat related illnesses increase significantly during
  extreme heat events.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors.

Do not leave young children and pets in unattended vehicles. Car
interiors will reach lethal temperatures in a matter of minutes.

&&

$$

CAZ050-191130-
/O.CON.KSGX.XH.A.0002.250821T1700Z-250823T0300Z/
San Diego County Valleys-
Including the cities of San Marcos, Escondido, Poway, El Cajon,
La Mesa, and Santee
822 PM PDT Mon Aug 18 2025

...EXTREME HEAT WATCH REMAINS IN EFFECT FROM THURSDAY MORNING
THROUGH FRIDAY EVENING...

* WHAT...Dangerously hot conditions with temperatures up to 100.

* WHERE...San Diego County Valleys.

* WHEN...From Thursday morning through Friday evening.

* IMPACTS...Heat related illnesses increase significantly during
  extreme heat events.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors.

&&

$$

CAZ055-056-058-191130-
/O.CON.KSGX.XH.A.0002.250821T1700Z-250823T0300Z/
San Bernardino County Mountains-Riverside County Mountains-San
Diego County Mountains-
Including the cities of Big Bear City, Wrightwood, Lake
Arrowhead, Big Bear Lake, Crestline, Pine Valley, Julian,
Idyllwild-Pine Cove, and Running Springs
822 PM PDT Mon Aug 18 2025

...EXTREME HEAT WATCH REMAINS IN EFFECT FROM THURSDAY MORNING
THROUGH FRIDAY EVENING...

* WHAT...Dangerously hot conditions with temperatures up to 98
  possible.

* WHERE...Riverside County Mountains, San Bernardino County
  Mountains, and San Diego County Mountains.

* WHEN...From Thursday morning through Friday evening.

* IMPACTS...Heat related illnesses increase significantly during
  extreme heat events.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors.

Do not leave young children and pets in unattended vehicles. Car
interiors will reach lethal temperatures in a matter of minutes.

&&

$$

CAZ057-554-191130-
/O.CON.KSGX.XH.A.0002.250821T1700Z-250823T0300Z/
Santa Ana Mountains and Foothills-Orange County Inland Areas-
Including the cities of Mission Viejo, Garden Grove, Anaheim,
Fullerton, Irvine, Santa Ana, and Orange
822 PM PDT Mon Aug 18 2025

...EXTREME HEAT WATCH REMAINS IN EFFECT FROM THURSDAY MORNING
THROUGH FRIDAY EVENING...

* WHAT...Dangerously hot conditions with temperatures up to 100.

* WHERE...Orange County Inland Areas and Santa Ana Mountains and
  Foothills.

* WHEN...From Thursday morning through Friday evening.

* IMPACTS...Heat related illnesses increase significantly during
  extreme heat events.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors.

&&

$$

CAZ060-191130-
/O.CON.KSGX.XH.A.0002.250821T1700Z-250823T0300Z/
Apple and Lucerne Valleys-
Including the cities of Apple Valley, Victorville, Lucerne
Valley, and Hesperia
822 PM PDT Mon Aug 18 2025

...EXTREME HEAT WATCH REMAINS IN EFFECT FROM THURSDAY MORNING
THROUGH FRIDAY EVENING...

* WHAT...Dangerously hot conditions with temperatures up to 106.

* WHERE...Apple and Lucerne Valleys.

* WHEN...From Thursday morning through Friday evening.

* IMPACTS...Heat related illnesses increase significantly during
  extreme heat events.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors.

Do not leave young children and pets in unattended vehicles. Car
interiors will reach lethal temperatures in a matter of minutes.

&&

$$

CAZ061-062-065-191130-
/O.CON.KSGX.XH.A.0002.250821T1700Z-250823T0300Z/
Coachella Valley-San Diego County Deserts-San Gorgonio Pass near
Banning-
Including the cities of Indio, La Quinta, Palm Desert, Palm
Springs, Borrego Springs, Cathedral City, Coachella, and Palm
Desert Country
822 PM PDT Mon Aug 18 2025

...EXTREME HEAT WATCH REMAINS IN EFFECT FROM THURSDAY MORNING
THROUGH FRIDAY EVENING...

* WHAT...Dangerously hot conditions with temperatures up to 114.

* WHERE...Coachella Valley, San Diego County Deserts, and San
  Gorgonio Pass near Banning.

* WHEN...From Thursday morning through Friday evening.

* IMPACTS...Heat related illnesses increase significantly during
  extreme heat events.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors.

Do not leave young children and pets in unattended vehicles. Car
interiors will reach lethal temperatures in a matter of minutes.

&&

$$

MM