34°53'N / 117°1'W / Altitude 659 m / 08:03 2026/07/28, America/Los_Angeles (UTC-7)
From: 2026/07/27, 23:12
To: 2026/07/28, 17:00
* WHAT...Dangerously hot conditions. Afternoon temperatures 109 to 121 expected. Major to Extreme Heat Risk. * WHERE...Portions of southwest Arizona and southeast and southern California. * WHEN...From 10 AM MST /10 AM PDT/ Thursday to 8 PM MST /8 PM PDT/ Sunday. * IMPACTS...Increase in heat related illnesses, including heat cramps, heat exhaustion, and heat stroke. Heat stroke can lead to death.
San Bernardino
An Extreme Heat Warning means that a period of very hot temperatures,
even by local standards, will occur. Actions should be taken to
lessen the impact of the extreme heat.
Take extra precautions if you work or spend time outside. When
possible, reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose-fitting clothing when possible and
drink plenty of water.
To reduce risk during outdoor work, the Occupational Safety and
Health Administration recommends scheduling frequent rest breaks in
shaded or air conditioned environments. Anyone overcome by heat
should be moved to a cool and shaded location. Heat stroke is an
emergency! Call 9 1 1.
Public cooling shelters are available in some areas. Consult county
officials for more details.
NWS Phoenix AZ
2026/07/27, 23:12From: 2026/07/28, 01:00
To: 2026/07/28, 16:00
* WHAT...Dangerously hot conditions with highs 110 to 120 degrees across the Mojave Desert. Highs 100 to 110 degrees across most of the southern Great Basin and Arizona Strip. Little to no overnight relief is expected, particularly in the Mojave Desert where lows of 80 to 95 degrees are forecast. This will result in major to extreme heat risk. * WHERE...Portions of northwest Arizona, southeast California, and south central and southern Nevada. * WHEN...From 10 AM PDT / MST Thursday to 8 PM PDT / MST Sunday. * IMPACTS...Heat related illnesses increase significantly during extreme heat events.
San Bernardino,Western Mojave DesertDrink 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.
Take extra precautions when outside. Wear lightweight and loose
fitting clothing. Try to limit strenuous activities to early morning
or evening. Take action when you see symptoms of heat exhaustion and
heat stroke.
To reduce risk during outdoor work, the Occupational Safety and
Health Administration recommends scheduling frequent rest breaks in
shaded or air conditioned environments. Anyone overcome by heat
should be moved to a cool and shaded location. Heat stroke is an
emergency! Call 9 1 1.
Monitor the latest forecasts and warnings for updates.NWS Las Vegas NV2026/07/28, 01:00From: 2026/07/28, 01:56
To: 2026/07/28, 15:45
* WHAT...Dangerously hot conditions with temperatures up to 110 expected. * WHERE...San Bernardino and Riverside County Valleys-The Inland Empire. * WHEN...From 10 AM Thursday to 8 PM PDT Sunday. * IMPACTS...Heat related illnesses increase significantly during extreme heat events.
San BernardinoDrink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors.NWS San Diego CA2026/07/28, 01:56From: 2026/07/28, 01:56
To: 2026/07/28, 15:45
* WHAT...Dangerously hot conditions with high temperatures up to 114 expected. * WHERE...Apple and Lucerne Valleys. * WHEN...From 10 AM Thursday to 8 PM PDT Sunday. * IMPACTS...Heat related illnesses increase significantly during extreme heat events.
San BernardinoDrink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors.NWS San Diego CA2026/07/28, 01:56
From: 2026/07/28, 01:56
To: 2026/07/28, 15:45
* WHAT...High temperatures in the 90s to around 100 below 7000 feet expected. * WHERE...San Bernardino County Mountains. * WHEN...From 10 AM Thursday to 8 PM PDT Sunday. * IMPACTS...Hot temperatures may cause heat illnesses.
San BernardinoDrink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors.NWS San Diego CA2026/07/28, 01:56