Extreme Heat Warning
URGENT - WEATHER MESSAGE
National Weather Service Tucson AZ
207 AM MST Wed Aug 20 2025
AZZ501>507-509-202300-
/O.CON.KTWC.XH.W.0006.250820T1700Z-250823T0300Z/
Western Pima County-Tohono O`odham Nation-Upper Santa Cruz River
Valley/Altar Valley-Tucson Metro Area-South Central Pinal County-
Southeast Pinal County-Upper San Pedro River Valley-Upper Gila
River Valley-
Including the cities of Sierra Vista, Nogales, Green Valley,
Clifton, Vail, Safford, Sells, Tucson, Mammoth, Picacho Peak
State Park, Ajo, Benson, Organ Pipe Cactus N.M., Marana, and
Oracle
207 AM MST Wed Aug 20 2025
...EXTREME HEAT WARNING REMAINS IN EFFECT FROM 10 AM THIS MORNING TO
8 PM MST FRIDAY...
* WHAT...Dangerously hot conditions with temperatures ranging from
105 to 110 across much of Pima and southeastern Pinal counties
leading to Major Heat Risk. In other areas of southeastern
Arizona, high temperatures will range from 100 to 105 degrees.
* WHERE...South Central Pinal County, Southeast Pinal County, Tohono
O`odham Nation, Tucson Metro Area, Upper Gila River Valley, Upper
San Pedro River Valley, Upper Santa Cruz River Valley/Altar
Valley, and Western Pima County.
* WHEN...From 10 AM this morning to 8 PM MST Friday.
* IMPACTS...Heat related illnesses increase significantly during
extreme heat events.
* ADDITIONAL DETAILS...Major Heat Risk is when heat will affect
anyone without cooling or hydration as well as health systems and
industries.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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.
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.
&&
$$
KJS
URGENT - WEATHER MESSAGE...CORRECTED
National Weather Service Flagstaff AZ
150 AM MST Wed Aug 20 2025
AZZ006-201700-
/O.CAN.KFGZ.XH.A.0003.250821T0300Z-250823T0300Z/
/O.COR.KFGZ.XH.W.0005.000000T0000Z-250823T0300Z/
Grand Canyon Country-
Including the cities of North Rim, Grand Canyon Village, and
Supai
150 AM MST Wed Aug 20 2025
...EXTREME HEAT WATCH IS CANCELLED...
...EXTREME HEAT WARNING NOW IN EFFECT UNTIL 8 PM MST FRIDAY BELOW
4000 FEET...
* WHAT...Dangerously hot conditions expected below 4000 feet, with
daytime temperatures ranging from 102 degrees at Havasupai
Gardens, to 112 degrees at Phantom Ranch.
* WHERE...Lower elevations of the Grand Canyon below 4000 feet.
* WHEN...Until 8 PM MST Friday.
* IMPACTS...Most individuals will be at risk for heat-related
illnesses without effective cooling or adequate hydration,
especially with prolonged outdoor exposure.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
This warning is reserved for only the hottest days of the year and
is issued when temperatures are expected to rise to dangerous levels.
Day hikers on Bright Angel Trail should descend no farther than 1
1/2 miles from the upper trailhead. Between the hours of 10 AM and 4
PM, hikers should be out of the canyon or at Havasupai Gardens or
Bright Angel campgrounds, physical activity is discouraged. All
hikers should have adequate gear, including a wide-brimmed hat,
sunscreen, salty snacks, sufficient water, and electrolyte mix.
Doubling your calorie intake helps maintain your energy.
Hike smart.
Take action when you see symptoms of heat exhaustion and heat
stroke. Anyone overcome by heat should be moved to a cool and shaded
location. Heat stroke is an emergency! Call 9 1 1.
Stay cool, stay hydrated, stay informed.
&&
$$
Humphreys
URGENT - WEATHER MESSAGE
National Weather Service Phoenix AZ
102 AM MST Wed Aug 20 2025
AZZ530>533-535-536-CAZ560>570-202230-
/O.CON.KPSR.XH.W.0007.250820T1700Z-250823T0300Z/
Parker Valley-Kofa-Yuma-Central La Paz-Southeast Yuma County-Gila
River Valley-Joshua Tree NP West-Joshua Tree NP East-Imperial
County Southwest-Salton Sea-Chuckwalla Mountains-Imperial County
Southeast-Imperial County West-Imperial Valley-Chiriaco Summit-
Palo Verde Valley-Chuckwalla Valley-
Including the cities of Coyote Wells, Winona, Mountain Spring,
Ripley, Calexico, Quartzsite, Ligurta, Yuma, Parker, Blythe,
Imperial Hot Mineral Springs, Alamorio, Desert Shores, Martinez
Lake, Vicksburg, Midland, Salton City, Ehrenberg, Brawley,
Chiriaco Summit, Palo Verde, Palm Canyon, Lost Horse-Keys
Village, Coolidge Springs, Brenda, Plaster City, Ocotillo,
Vicksburg Junction, Cottonwood Visitor, Winterhaven, Fortuna
Foothills, El Centro, Harcuvar, and Salome
102 AM MST Wed Aug 20 2025 /102 AM PDT Wed Aug 20 2025/
...EXTREME HEAT WARNING REMAINS IN EFFECT FROM 10 AM MST /10 AM PDT/
THIS MORNING TO 8 PM MST /8 PM PDT/ FRIDAY...
* WHAT...Dangerously hot conditions. Afternoon temperatures 107 to
115 expected. Major Heat Risk.
* WHERE...Portions of southwest Arizona and southeast and southern
California.
* WHEN...From 10 AM MST /10 AM PDT/ this morning to 8 PM MST /8 PM
PDT/ Friday.
* IMPACTS...Heat related illnesses increase significantly during
extreme heat events. Overexposure can cause heat cramps and heat
exhaustion to develop and, without intervention, can lead to heat
stroke.
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.
&&
$$
URGENT - WEATHER MESSAGE
National Weather Service Phoenix AZ
102 AM MST Wed Aug 20 2025
AZZ534-538-539-541-545-547-549-552>556-559-560-562-202230-
/O.CON.KPSR.XH.W.0007.250820T1700Z-250823T0300Z/
Aguila Valley-Tonopah Desert-Gila Bend-Cave Creek/New River-New
River Mesa-Rio Verde/Salt River-Fountain Hills/East Mesa-Superior-
Northwest Pinal County-West Pinal County-Apache Junction/Gold
Canyon-Tonto Basin-Sonoran Desert Natl Monument-San Carlos-
Globe/Miami-
Including the cities of Tortilla Flat, Superior, Gladden,
Tonopah, Fountain Hills, Scottsdale, Apache Junction, Coolidge,
Gila Bend, Wickenburg, Wintersburg, Peridot, Hassayampa, Cactus
Forest, Kaka, Globe, San Carlos, Casa Grande, Arlington, Miami,
Punkin Center, Sentinel, Florence, and Aguila
102 AM MST Wed Aug 20 2025
...EXTREME HEAT WARNING REMAINS IN EFFECT FROM 10 AM THIS MORNING TO
8 PM MST FRIDAY...
* WHAT...Dangerously hot conditions. Afternoon temperatures 106 to
114 expected. Major Heat Risk.
* 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. Overexposure can cause heat cramps and heat
exhaustion to develop and, without intervention, can lead to heat
stroke.
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.
&&
$$
URGENT - WEATHER MESSAGE
National Weather Service Phoenix AZ
102 AM MST Wed Aug 20 2025
AZZ537-540-542>544-546-548-550-551-202230-
/O.CON.KPSR.XH.W.0007.250820T1700Z-250823T0300Z/
Northwest Valley-Buckeye/Avondale-Deer Valley-Central Phoenix-
North Phoenix/Glendale-Scottsdale/Paradise Valley-East Valley-
South Mountain/Ahwatukee-Southeast Valley/Queen Creek-
Including the cities of Sun Lakes, Chandler, Phoenix, Wittmann,
Beardsley, Gilbert, Circle City, Queen Creek, Peoria, Cashion,
Sun City West, Tempe, Surprise, Paradise Valley, Mesa, Avondale,
Goodyear, and Liberty
102 AM MST Wed Aug 20 2025
...EXTREME HEAT WARNING REMAINS IN EFFECT FROM 10 AM THIS MORNING TO
8 PM MST FRIDAY...
* WHAT...Dangerously hot conditions. Afternoon temperatures 109 to
114 expected. Major Heat Risk.
* WHERE...The Northwest Valley of the Phoenix Metro Area, The East
Valley of the Phoenix Metro Area, Buckeye/Avondale, Deer Valley,
Central Phoenix, North Phoenix/Glendale, Scottsdale/Paradise
Valley, South Mountain/Ahwatukee, and Southeast Valley/Queen Creek.
* WHEN...From 10 AM this morning to 8 PM MST Friday.
* IMPACTS...Heat related illnesses increase significantly during
extreme heat events. Overexposure can cause heat cramps and heat
exhaustion to develop and, without intervention, can lead to heat
stroke.
* ADDITIONAL DETAILS...In Maricopa County, call 2-1-1 to find a free
cooling center, transportation, water, and more.
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.
&&
$$
URGENT - WEATHER MESSAGE
National Weather Service Salt Lake City UT
1249 AM MDT Wed Aug 20 2025
UTZ123-124-210000-
/O.UPG.KSLC.XH.A.0001.250821T1800Z-250823T0300Z/
/O.NEW.KSLC.XH.W.0003.250821T1800Z-250823T0300Z/
Lower Washington County-Zion National Park-
Including the following locations - Ivins, St George, Hurricane,
and Springdale
1249 AM MDT Wed Aug 20 2025
...EXTREME HEAT WARNING IN EFFECT FROM NOON THURSDAY TO 9 PM MDT
FRIDAY...
* WHAT...Dangerously hot conditions with temperatures up to 108
expected. Overnight temperatures in the upper 70s to low 80s will
prolong heat stress to those without proper cooling.
* WHERE...Lower Washington County and Zion National Park.
* WHEN...From noon Thursday to 9 PM MDT Friday.
* IMPACTS...Heat related illnesses increase significantly during
extreme heat events.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Drink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors.
Do not leave young children and pets in unattended vehicles. Car
interiors will reach lethal temperatures in a matter of minutes.
Take extra precautions when outside. Wear lightweight and loose
fitting clothing. Try to limit strenuous activities to early morning
or evening. Take action when you see symptoms of heat exhaustion and
heat stroke.
To reduce risk during outdoor work, the Occupational Safety and
Health Administration recommends scheduling frequent rest breaks in
shaded or air conditioned environments. Anyone overcome by heat
should be moved to a cool and shaded location. Heat stroke is an
emergency! Call 9 1 1.
&&
$$
For more information from the National Weather Service visit
https://weather.gov/saltlakecity.
For information on potential travel impacts visit
http://udottraffic.utah.gov
BW
URGENT - WEATHER MESSAGE
National Weather Service Las Vegas NV
421 AM PDT Tue Aug 19 2025
AZZ001>003-036-CAZ520-522>527-NVZ015>017-020>022-201500-
/O.CON.KVEF.XH.W.0009.250820T1500Z-250824T0600Z/
Northwest Plateau-Lake Havasu and Fort Mohave-Northwest Deserts-
Lake Mead National Recreation Area-Owens Valley-Death Valley
National Park-Western Mojave Desert-Eastern Mojave Desert-Morongo
Basin-Cadiz Basin-San Bernardino County-Upper Colorado River
Valley-Lincoln County-Northeast Clark County-Western Clark and
Southern Nye County-Las Vegas Valley-Lake Mead National
Recreation Area-Southern Clark County-
Including the cities of Shoshone, Yucca, Pahrump, Baker,
Twentynine Palms, Mountain Pass, Bullhead City, Mesquite, Furnace
Creek, Vidal Junction, Pioche, Desert Rock, Bishop, Lone Pine,
Laughlin, North Las Vegas, Overton, Pipe Spring National
Monument, Oatman, Las Vegas, Alamo, Stovepipe Wells, Mitchell
Caverns, Valentine, Topock, Mt Trumbull, Hoover Dam, Barstow,
Moapa, Searchlight, Desert Hills, Wikieup, Morongo Valley,
Needles, Panaca, Dolan Springs, Olancha, Western Grand Canyon,
Cal-Nev-Ari, Mohave Valley, Yucca Valley, Indian Springs,
Kingman, Hiko, Rachel, Boulder City, Lake Havasu City, Amargosa
Valley, Tuweep, Henderson, Daggett, Primm, Independence, Fort
Irwin, Caliente, Golden Valley, and Colorado City
421 AM PDT Tue Aug 19 2025 /421 AM MST Tue Aug 19 2025/
...EXTREME HEAT WARNING REMAINS IN EFFECT FROM 8 AM PDT /8 AM MST/
WEDNESDAY TO 11 PM PDT /11 PM MST/ SATURDAY...
* WHAT...Dangerously hot conditions with temperatures around 105 in
Kingman, Golden Valley, Dolan Springs; around 110 in Las Vegas,
Pahrump, Barstow, Yucca Valley, Twentynine Palms; around 115 in
Laughlin, Bullhead City, Needles, Lake Havasu City; around 120 at
Furnace Creek in Death Valley National Park. Expect minimal
overnight relief. Major-to-Extreme Heat Risk. In the Owens Valley,
temperatures will be around 100 to 105, yielding Moderate Heat
Risk.
* WHERE...Portions of northwest Arizona, southeast California, and
south central and southern Nevada.
* WHEN...From 8 AM PDT /8 AM MST/ Wednesday to 11 PM PDT /11 PM MST/
Saturday.
* 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.
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.
&&
$$
Heat Advisory
URGENT - WEATHER MESSAGE
National Weather Service Las Vegas NV
421 AM PDT Tue Aug 19 2025
NVZ014-018-019-201500-
/O.CON.KVEF.HT.Y.0003.250820T1500Z-250824T0600Z/
Esmeralda and Central Nye County-Sheep Range-Spring Mountains-Red
Rock Canyon-
Including the cities of Hayford Pk, Mt Charleston, Red Rock
Canyon, Goldfield, Beatty, Dyer, and Silver Peak
421 AM PDT Tue Aug 19 2025
...HEAT ADVISORY REMAINS IN EFFECT FROM 8 AM WEDNESDAY TO 11 PM PDT
SATURDAY...
* WHAT...Above-normal temperatures with afternoon highs in the
low-to-mid 80s for Mount Charleston, Lee Canyon, and Kyle Canyon.
Above-normal temperatures with afternoon highs between 95 and 100
for Goldfield; Tonopah; between 100 and 105 for Beatty. Expect
minimal overnight recovery. Moderate-to-High Heat Risk.
* WHERE...Esmeralda and Central Nye County, Sheep Range, and Spring
Mountains-Red Rock Canyon.
* WHEN...From 8 AM Wednesday to 11 PM PDT Saturday.
* IMPACTS...Hot temperatures may cause heat illnesses.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Drink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors.
Take extra precautions when outside. Wear lightweight and loose
fitting clothing. Try to limit strenuous activities to early morning
or evening. Take action when you see symptoms of heat exhaustion and
heat stroke.
To reduce risk during outdoor work, the Occupational Safety and
Health Administration recommends scheduling frequent rest breaks in
shaded or air conditioned environments. Anyone overcome by heat
should be moved to a cool and shaded location. Heat stroke is an
emergency! Call 9 1 1.
Monitor the latest forecasts and warnings for updates.
&&
$$
For more information from the National Weather Service visit
http://weather.gov/lasvegas
MS
Hazardous Weather Outlook
Hazardous Weather Outlook
National Weather Service Grand Junction CO
308 AM MDT Wed Aug 20 2025
COZ001>014-017>023-UTZ022>025-027>029-210915-
Lower Yampa River Basin-Central Yampa River Basin-
Roan and Tavaputs Plateaus-Elkhead and Park Mountains-
Upper Yampa River Basin-Grand Valley-Debeque to Silt Corridor-
Central Colorado River Basin-Grand and Battlement Mesas-
Gore and Elk Mountains/Central Mountain Valleys-
Central Gunnison and Uncompahgre River Basin-
West Elk and Sawatch Mountains-Flat Tops-Upper Gunnison River Valley-
Uncompahgre Plateau and Dallas Divide-Northwest San Juan Mountains-
Southwest San Juan Mountains-Paradox Valley/Lower Dolores River-
Four Corners/Upper Dolores River-Animas River Basin-
San Juan River Basin-Southeast Utah-Eastern Uinta Mountains-
Eastern Uinta Basin-Tavaputs Plateau-Arches/Grand Flat-
La Sal and Abajo Mountains-Canyonlands/Natural Bridges-
308 AM MDT Wed Aug 20 2025
This Hazardous Weather Outlook is for northwest Colorado, southwest
Colorado, west central Colorado, east central Utah, northeast Utah
and southeast Utah.
.DAY ONE...Today and tonight.
Isolated terrain-based storms are possible this afternoon. Storms
will be capable of producing gusty outflow winds up to 40 mph. Near
record high temperatures expected.
.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.
Isolated thunderstorm chances continue over the higher terrain
before increasing in coverage daily starting tomorrow. Chances of
wetting rain come up for Saturday onward.
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected at this time.
$$
