Extreme Heat Warning
URGENT - WEATHER MESSAGE
National Weather Service Phoenix AZ
1254 AM MST Wed Jun 18 2025
AZZ534-538-539-547-552>556-559>562-182200-
/O.CON.KPSR.XH.W.0002.250618T1700Z-250621T0300Z/
Aguila Valley-Tonopah Desert-Gila Bend-Rio Verde/Salt River-
Superior-Northwest Pinal County-West Pinal County-Apache
Junction/Gold Canyon-Tonto Basin-Sonoran Desert Natl Monument-San
Carlos-Dripping Springs-Globe/Miami-
Including the cities of San Carlos, Cactus Forest, Arlington,
Hassayampa, Peridot, Casa Grande, Sentinel, Hayden, Gladden,
Aguila, Superior, Coolidge, Wintersburg, Winkelman, Miami,
Wickenburg, Tonopah, Apache Junction, Punkin Center, Kaka, Globe,
Gila Bend, Tortilla Flat, and Florence
1254 AM MST Wed Jun 18 2025
...EXTREME HEAT WARNING REMAINS IN EFFECT FROM 10 AM THIS MORNING TO
8 PM MST FRIDAY...
* WHAT...Dangerously hot conditions. Afternoon temperatures 105 to
117 expected. Major Heat Risk. Overexposure can cause heat cramps
and heat exhaustion to develop and, without intervention, can lead
to heat stroke.
* WHERE...A portion of south central Arizona.
* WHEN...From 10 AM this morning to 8 PM MST Friday.
* IMPACTS...Heat related illnesses increase significantly during
extreme heat events.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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.
&&
$$
CK
URGENT - WEATHER MESSAGE
National Weather Service Flagstaff AZ
905 PM MST Tue Jun 17 2025
AZZ006-181215-
/O.CON.KFGZ.XH.W.0001.000000T0000Z-250621T0200Z/
Grand Canyon Country-
Including the cities of North Rim, Supai, and Grand Canyon
Village
905 PM MST Tue Jun 17 2025
...EXTREME HEAT WARNING REMAINS IN EFFECT UNTIL 7 PM MST FRIDAY
BELOW 4000 FEET...
* WHAT...Dangerously hot conditions below 4000 feet, with daytime
temperatures ranging from 104 degrees at Havasupai Gardens, to 114
degrees at Phantom Ranch.
* WHERE...Lower elevations of the Grand Canyon.
* WHEN...Until 7 PM MST Friday.
* IMPACTS...Most individuals will be at risk for heat-related
illnesses without effective cooling or adequate hydration,
especially with prolonged outdoor exposure.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
This warning is reserved for only the hottest days of the year and
is issued when temperatures are expected to rise to dangerous levels.
Day hikers on Bright Angel Trail should descend no farther than 1
1/2 miles from the upper trailhead. Between the hours of 10 AM and 4
PM, hikers should be out of the canyon or at Havasupai Gardens or
Bright Angel campgrounds, physical activity is discouraged. All
hikers should have adequate gear, including a wide-brimmed hat,
sunscreen, salty snacks, sufficient water, and electrolyte mix.
Doubling your calorie intake helps maintain your energy.
Hike smart.
&&
$$
Humphreys
URGENT - WEATHER MESSAGE
National Weather Service Las Vegas NV
1255 PM PDT Tue Jun 17 2025
AZZ002-003-036-CAZ522>524-527-NVZ017-020-021-181800-
/O.CON.KVEF.XH.W.0004.250618T1700Z-250620T0500Z/
Lake Havasu and Fort Mohave-Northwest Deserts-Lake Mead National
Recreation Area-Death Valley National Park-Western Mojave Desert-
Eastern Mojave Desert-San Bernardino County-Upper Colorado River
Valley-Western Clark and Southern Nye County-Las Vegas Valley-
Lake Mead National Recreation Area-
Including the cities of Pahrump, Hoover Dam, North Las Vegas,
Indian Springs, Kingman, Mohave Valley, Yucca, Laughlin, Wikieup,
Desert Rock, Amargosa Valley, Henderson, Daggett, Desert Hills,
Las Vegas, Lake Havasu City, Golden Valley, Mitchell Caverns,
Fort Irwin, Baker, Stovepipe Wells, Bullhead City, Topock,
Valentine, Furnace Creek, Needles, Dolan Springs, Mountain Pass,
Boulder City, Barstow, Shoshone, and Oatman
1255 PM PDT Tue Jun 17 2025 /1255 PM MST Tue Jun 17 2025/
...EXTREME HEAT WARNING REMAINS IN EFFECT FROM 10 AM PDT /10 AM MST/
WEDNESDAY TO 10 PM PDT /10 PM MST/ THURSDAY...
* WHAT...Dangerously hot conditions with temperatures of 110 to 115
degrees expected.
* WHERE...Lake Mead National Recreation Area, Lake Havasu and Fort
Mohave, Northwest Deserts, Death Valley National Park, Western
Mojave Desert, Eastern Mojave Desert, San Bernardino County-Upper
Colorado River Valley, Western Clark and Southern Nye County, and
Las Vegas Valley.
* WHEN...From 10 AM PDT /10 AM MST/ Wednesday to 10 PM PDT /10 PM
MST/ Thursday.
* IMPACTS...Heat related illnesses increase significantly during
extreme heat events, especially when overnight low temperatures
remain warm. This results in little to no time to recover from the
heat.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Drink plenty of fluids, stay in an air-conditioned room as much as
possible, and stay out of the sun. Check in with 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.
&&
$$
For more information from the National Weather Service visit
http://weather.gov/lasvegas
MA
Red Flag Warning
URGENT - FIRE WEATHER MESSAGE
National Weather Service Salt Lake City UT
219 AM MDT Wed Jun 18 2025
UTZ482>484-489-492>498-181630-
/O.CON.KSLC.FW.W.0002.250619T1800Z-250622T0400Z/
Western Uintah Basin-Southern Ashley National Forest-
Tavaputs Plateau-San Rafael Swell-Central Utah West Desert-
Central Utah Mountains-Henry Mountains-Color Country West Desert-
Color Country Mountains-Mojave Desert-Grand Staircase-
219 AM MDT Wed Jun 18 2025
...RED FLAG WARNING REMAINS IN EFFECT FROM NOON THURSDAY TO 10 PM
MDT SATURDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER
ZONES 482, 483, 484, 489, 492, 493, 494, 495, 496, 497, AND 498...
* AFFECTED AREA...Fire Weather Zone 482 Western Uintah Basin,
Fire Weather Zone 483 Southern Ashley National Forest, Fire
Weather Zone 484 Tavaputs Plateau, Fire Weather Zone 489 San
Rafael Swell, Fire Weather Zone 492 Central Utah West Desert,
Fire Weather Zone 493 Central Utah Mountains, Fire Weather
Zone 494 Henry Mountains, Fire Weather Zone 495 Color Country
West Desert, Fire Weather Zone 496 Color Country Mountains,
Fire Weather Zone 497 Mojave Desert and Fire Weather Zone 498
Grand Staircase.
* WINDS...For Thursday, south to southwest winds 10 to 20 mph with
gusts 30 to 35 mph, increasing on Friday to 15 to 25 mph with
gusts 35 to 40 mph. The strongest winds are expected Saturday
afternoon and evening, with sustained winds 20 to 30 mph with
gusts 40 to 45 mph or greater.
* RELATIVE HUMIDITY...Falling into the 5 to 9 percent range each
afternoon with poor overnight recovery of 15-25 percent
Thursday and Friday nights.
* IMPACTS...Critical fire weather conditions are expected. Any
new fire starts or existing fires may spread rapidly.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Red Flag Warning means that critical fire weather conditions
are expected. A combination of strong winds...low relative
humidity...and warm temperatures can contribute to extreme fire
behavior.
&&
$$
For more information from the National Weather Service visit
http://weather.gov/saltlakecity
Heat Advisory
URGENT - WEATHER MESSAGE
National Weather Service San Diego CA
1238 PM PDT Tue Jun 17 2025
CAZ048-050-056-058-180500-
/O.CON.KSGX.HT.Y.0002.000000T0000Z-250619T0300Z/
San Bernardino and Riverside County Valleys-The Inland Empire-San
Diego County Valleys-Riverside County Mountains-San Diego County
Mountains-
Including the cities of Julian, Riverside, Poway, Escondido, El
Cajon, Pine Valley, San Marcos, Santee, Rancho Cucamonga, San
Bernardino, Moreno Valley, Fontana, Ontario, and Corona
1238 PM PDT Tue Jun 17 2025
...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM PDT WEDNESDAY...
* WHAT...High temperatures mostly in the 90s for the Inland Empire,
the inland San Diego County valleys, and the mountains below 4500
feet.
* WHERE...Riverside County Mountains, San Bernardino and Riverside
County Valleys-The Inland Empire, San Diego County Mountains, and
San Diego County Valleys.
* WHEN...Until 8 PM PDT Wednesday.
* IMPACTS...Widespread Moderate HeatRisk. Hot temperatures may cause
heat illnesses.
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.
&&
$$
APR
Fire Weather Watch
URGENT - FIRE WEATHER MESSAGE
National Weather Service Reno NV
124 PM PDT Tue Jun 17 2025
CAZ274-278-NVZ420-421-423-429-458-182030-
/O.NEW.KREV.FW.A.0004.250619T2000Z-250621T0700Z/
Southern Mono County-Eastern Lassen County-
Northern Sierra Front including Carson City, Douglas, Storey,
Southern Washoe, Western Lyon, and Far Southern Lassen Counties-
Southern Sierra Front including Alpine, Northern Mono, Southern
Lyon, and Western Mineral Counties-
West Humboldt Basin in Pershing County-
Lahontan Basin including Churchill and Eastern Mineral Counties-
Northern Washoe County-
124 PM PDT Tue Jun 17 2025
...FIRE WEATHER WATCH IN EFFECT FROM THURSDAY AFTERNOON THROUGH
FRIDAY EVENING FOR GUSTY WINDS AND LOW HUMIDITY FOR WESTERN
NEVADA, EASTERN LASSEN COUNTY, AND ALPINE AND MONO COUNTIES...
The National Weather Service in Reno has issued a Fire Weather
Watch for gusty winds and low humidity, which is in effect from
Thursday afternoon through Friday evening.
* Affected Area...Fire Weather Zone 274 Southern Mono County,
Fire Weather Zone 278 Eastern Lassen County, Fire Weather Zone
420 Northern Sierra Front including Carson City, Douglas,
Storey, Southern Washoe, Western Lyon, and Far Southern Lassen
Counties, Fire Weather Zone 421 Southern Sierra Front
including Alpine, Northern Mono, Southern Lyon, and Western
Mineral Counties, Fire Weather Zone 423 West Humboldt Basin in
Pershing County, Fire Weather Zone 429 Lahontan Basin
including Churchill and Eastern Mineral Counties and Fire
Weather Zone 458 Northern Washoe County.
* Winds...For Thursday, southwest to west 15-20 mph gusting to
30-35 mph. For Friday, southwest to west 20-25 mph gusting to
35-40 mph. Wind prone areas Friday may reach up to 50 mph.
* Humidity...For Thursday, minimum humidity 8-15% in the
afternoon. For Friday, minimum humidity 5-15% in the afternoon.
Limited overnight recoveries Friday morning of 20-30%.
* Duration...For Thursday, 3 to 6 hours. For Friday, 4 to 9
hours.
* Impacts...The combination of gusty winds and low humidity can
cause fire to rapidly grow in size and intensity before first
responders can contain them.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Avoid outdoor activities that can cause a spark near dry
vegetation, such as yard work, target shooting, or campfires.
Follow local fire restrictions. Check weather.gov/reno for
updates and livingwithfire.info for preparedness tips.
&&
$$
http://weather.gov/reno
Air Quality Alert
AZC013-190400-
Air Quality Alert
Relayed by National Weather Service Phoenix AZ
935 AM MST Tue Jun 17 2025
...OZONE HIGH POLLUTION ADVISORY FOR MARICOPA COUNTY INCLUDING THE
PHOENIX METRO AREA WEDNESDAY...
The Arizona Department of Environmental Quality (ADEQ) has issued an
Ozone High Pollution Advisory for the Phoenix Metro Area on
Wednesday.
This means that forecast weather conditions combined with existing
ozone levels are expected to result in local maximum 8-hour ozone
concentrations that pose a health risk. Adverse health effects
increase as air quality deteriorates.
Ozone is an air contaminant which can cause breathing difficulties
for children, older adults, as well as persons with respiratory
problems. A decrease in physical activity is recommended.
You are urged to car pool, telecommute or use mass transit.
The use of gasoline-powered equipment should be reduced or done late
in the day.
For details on this High Pollution Advisory, visit the ADEQ internet
site at www.azdeq.gov/forecast/phoenix or call 602-771-2300.
$$
