Grand Canyon National Park, Arizona

Regional Weather Alerts


     

Alert: Flood Advisory
Area(s): Gila, AZ
Effective: 2026-08-20 @ 1:24 am -> 2026-08-20 @ 1:34 am
Onset: 2026-08-20 @ 1:24 am -> 2026-08-20 @ 1:30 am
Severity: Minor
Certainty: Likely
Urgency: Expected
Issued By: NWS Phoenix AZ on 2026-08-20 @ 1:24 am
Headline: Flood Advisory issued August 19 at 11:24PM MST until August 19 at 11:30PM MST by NWS Phoenix AZ
Description: The Flood Advisory will expire at 1130 PM MST this evening for a
portion of east central Arizona, including the following area, Gila.

The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.

Alert: Dust Advisory
Area(s): Maricopa, AZ; Pinal, AZ
Effective: 2026-08-20 @ 1:01 am -> 2026-08-20 @ 2:00 am
Onset: 2026-08-20 @ 1:01 am -> 2026-08-20 @ 2:00 am
Severity: Moderate
Certainty: Likely
Urgency: Expected
Issued By: NWS Phoenix AZ on 2026-08-20 @ 1:01 am
Headline: Dust Advisory issued August 19 at 11:01PM MST until August 20 at 12:00AM MST by NWS Phoenix AZ
Description: The National Weather Service in Phoenix has issued a

* Dust Advisory for...
Maricopa County in south central Arizona...
Pinal County in southeastern Arizona...

* Until midnight MST.

* At 1101 PM MST, a dust channel was near Bosque, or 11 miles east of
Gila Bend, moving west at 25 mph.

HAZARD...Less than two miles visibility with strong wind in excess
of 50 mph.

SOURCE...Doppler radar.

IMPACT...Hazardous travel.

* This includes the following highways...
AZ Interstate 8 between mile markers 90 and 140.
AZ Route 238 between mile markers 1 and 22.
AZ Route 85 between mile markers 1 and 137.

Locations impacted include...
Gila Bend, Estrella, Big Horn, Gila Bend Auxiliary Field, Bosque,
Cotton Center, Sonoran National Monument, and Sundad.

Alert: Dust Storm Warning
Area(s): Maricopa, AZ
Effective: 2026-08-20 @ 12:59 am -> 2026-08-20 @ 2:00 am
Onset: 2026-08-20 @ 12:59 am -> 2026-08-20 @ 2:00 am
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Phoenix AZ on 2026-08-20 @ 12:59 am
Headline: Dust Storm Warning issued August 19 at 10:59PM MST until August 20 at 12:00AM MST by NWS Phoenix AZ
Description: The National Weather Service in Phoenix has issued a

* Dust Storm Warning for...
Maricopa County in south central Arizona...

* Until midnight MST.

* At 1059 PM MST, a dust channel was near Buckeye, moving west at 30
mph.

HAZARD...Less than a quarter mile visibility with strong wind in
excess of 50 mph.

SOURCE...Doppler radar.

IMPACT...Dangerous life-threatening travel.

* This includes the following highways...
AZ Interstate 10 between mile markers 81 and 126.
AZ Route 85 between mile markers 138 and 154.
AZ Route 303 between mile markers 105 and 111.

Locations impacted include...
Goodyear, Buckeye, Tonopah, Palo Verde, Perryville, White Tank
Mountain Park, Liberty, Painted Rock Dam, Palo Verde Nuclear
Generation Station, Wintersburg, Estrella Mountain Ranch, Hassayampa,
and Arlington.

Alert: Special Weather Statement
Area(s): Aguila Valley; Northwest Valley; Tonopah Desert; Buckeye/Avondale; Cave Creek/New River; Deer Valley; North Phoenix/Glendale; New River Mesa; Rio Verde/Salt River; Mazatzal Mountains
Effective: 2026-08-20 @ 12:29 am -> 2026-08-20 @ 1:30 am
Onset: 2026-08-20 @ 12:29 am
Severity: Moderate
Certainty: Observed
Urgency: Expected
Issued By: NWS Phoenix AZ on 2026-08-20 @ 12:29 am
Headline: Special Weather Statement issued August 19 at 10:29PM MST by NWS Phoenix AZ
Description: At 1028 PM MST, Doppler radar was tracking an outflow boundary near
New River, moving northwest at 35 mph.

HAZARD...Wind gusts up to 55 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.

Locations impacted include...
Phoenix, Glendale, Scottsdale, Peoria, Surprise, Goodyear, Buckeye,
El Mirage, Youngtown, New River, Sun City West, Waddell, Circle City,
Sun City, Wittmann, Litchfield Park, Cave Creek, Carefree, Deer
Valley Airport, and White Tank Mountain Park.

This includes the following highways...
AZ Interstate 10 between mile markers 116 and 125.
AZ Interstate 17 between mile markers 212 and 241.
US Highway 60 between mile markers 120 and 152.

Alert: Flood Advisory
Area(s): Pima, AZ
Effective: 2026-08-20 @ 12:18 am -> 2026-08-20 @ 3:15 am
Onset: 2026-08-20 @ 12:18 am -> 2026-08-20 @ 3:15 am
Severity: Minor
Certainty: Likely
Urgency: Expected
Issued By: NWS Tucson AZ on 2026-08-20 @ 12:18 am
Headline: Flood Advisory issued August 19 at 10:18PM MST until August 20 at 1:15AM MST by NWS Tucson AZ
Description: * WHAT...Small stream flooding of normally dry washes caused by
excessive rainfall is expected to continue.

* WHERE...Southern Pima County in southeastern Arizona...

* WHEN...Until 115 AM MST.

* IMPACTS...Minor flooding in low-lying and poor drainage areas.

* ADDITIONAL DETAILS...
- At 1018 PM MST, Doppler radar indicated 1 to 2.5 inches of heavy
rain has fallen this evening along and west of the Baboquivari
Mountains. Minor small stream flooding of the normally dry
washes, roadway dips and other low-lying areas that drain from
this area will persist into the early morning hours. This
flooding will especially impact Route 19 or San Miguel Road south
of Topawa.
- Some locations that will experience flooding include...
Topawa, Vamori, South Komelik and Coldfields.
- This includes the following Flash Flood Prone Locations...
Indian Route 19 south of Topawa.
- http://www.weather.gov/safety/flood

Alert: Flood Advisory
Area(s): Pinal, AZ
Effective: 2026-08-20 @ 12:11 am -> 2026-08-20 @ 3:15 am
Onset: 2026-08-20 @ 12:11 am -> 2026-08-20 @ 3:15 am
Severity: Minor
Certainty: Likely
Urgency: Expected
Issued By: NWS Phoenix AZ on 2026-08-20 @ 12:11 am
Headline: Flood Advisory issued August 19 at 10:11PM MST until August 20 at 1:15AM MST by NWS Phoenix AZ
Description: * WHAT...Flooding caused by excessive rainfall is expected.

* WHERE...Pinal County in southeastern Arizona...

* WHEN...Until 115 AM MST.

* IMPACTS...Minor flooding in low-lying and poor drainage areas.

* ADDITIONAL DETAILS...
- At 1011 PM MST, A trained weather spotter reported 0.71 inches of
rain in 30 minutes in the advisory area. Minor flooding is
ongoing or expected to begin shortly. Between 0.5 and 1.5 inches
of rain have fallen.
- Additional rainfall amounts of 0.5 to 1 inch are expected over
the area. This additional rain will result in minor flooding.
- Some locations that will experience flooding include...
Florence, Coolidge, Queen Creek, Magma, San Tan Valley and San
Tan Mountain Park.
- http://www.weather.gov/safety/flood

Alert: Extreme Heat Warning
Area(s): Upper Gila River and Aravaipa Valleys including Clifton/Safford
Effective: 2026-08-19 @ 11:51 pm -> 2026-08-20 @ 7:00 pm
Onset: 2026-08-19 @ 11:51 pm -> 2026-08-21 @ 10:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Tucson AZ on 2026-08-19 @ 11:51 pm
Headline: Extreme Heat Warning issued August 19 at 9:51PM MST until August 21 at 8:00PM MST by NWS Tucson AZ
Description: * WHAT...Dangerously hot conditions with high temperatures ranging
between 103 to 107 degrees and low temperatures 75 to 81 degrees.
Major HeatRisk is expected.

* WHERE...Portions of Graham and southern Greenlee counties including
the Upper Gila River Valley.

* WHEN...Until 8 PM MST Friday.

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

Alert: Extreme Heat Warning
Area(s): Western Pima County Including Ajo/Organ Pipe Cactus National Monument; Tohono O'odham Nation including Sells; Tucson Metro Area including Tucson/Green Valley/Marana/Vail; South Central Pinal County including Eloy/Picacho Peak State Park; Southeast Pinal County including Kearny/Mammoth/Oracle
Effective: 2026-08-19 @ 11:51 pm -> 2026-08-20 @ 7:00 pm
Onset: 2026-08-19 @ 11:51 pm -> 2026-08-21 @ 10:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Tucson AZ on 2026-08-19 @ 11:51 pm
Headline: Extreme Heat Warning issued August 19 at 9:51PM MST until August 21 at 8:00PM MST by NWS Tucson AZ
Description: * WHAT...Dangerously hot conditions with high temperatures ranging
between 103 to 110 degrees and low temperatures 79 to 85 degrees.
Major HeatRisk is expected.

* WHERE...Pinal County, Tohono O'odham Nation, Tucson Metro Area, and
Western Pima County.

* WHEN...Until 8 PM MST Friday.

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

Alert: Flash Flood Warning
Area(s): Pinal, AZ
Effective: 2026-08-19 @ 11:29 pm -> 2026-08-20 @ 2:30 am
Onset: 2026-08-19 @ 11:29 pm -> 2026-08-20 @ 2:30 am
Severity: Severe
Certainty: Likely
Urgency: Immediate
Issued By: NWS Phoenix AZ on 2026-08-19 @ 11:29 pm
Headline: Flash Flood Warning issued August 19 at 9:29PM MST until August 20 at 12:30AM MST by NWS Phoenix AZ
Description: FFWPSR

The National Weather Service in Phoenix has issued a

* Flash Flood Warning for...
Pinal County in southeastern Arizona...

* Until 1230 AM MST.

* At 929 PM MST, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rain across the warned area. Between
1 and 1.5 inches of rain have fallen. Additional rainfall amounts
of 0.5 to 1 inch are possible in the warned area. Flash flooding is
ongoing or expected to begin shortly.

HAZARD...Life threatening flash flooding. Thunderstorms producing
flash flooding.

SOURCE...Radar and automated gauges.

IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
Florence.

Alert: Special Weather Statement
Area(s): Northwest Valley; Tonopah Desert; Buckeye/Avondale; Cave Creek/New River; Deer Valley; Central Phoenix; North Phoenix/Glendale; New River Mesa; Scottsdale/Paradise Valley; Rio Verde/Salt River; East Valley; Fountain Hills/East Mesa; South Mountain/Ahwatukee; Southeast Valley/Queen Creek; Superior; Northwest Pinal County; West Pinal County; Apache Junction/Gold Canyon; Tonto Basin; Mazatzal Mountains; Pinal/Superstition Mountains; Sonoran Desert Natl Monument; Globe/Miami
Effective: 2026-08-19 @ 10:23 pm -> 2026-08-20 @ 1:30 am
Onset: 2026-08-19 @ 10:23 pm
Severity: Moderate
Certainty: Observed
Urgency: Expected
Issued By: NWS Phoenix AZ on 2026-08-19 @ 10:23 pm
Headline: Special Weather Statement issued August 19 at 8:23PM MST by NWS Phoenix AZ
Description: At 823 PM MST, radar indicated strong thunderstorms were located near
Randolph, or near Coolidge, moving northwest at 25 mph.

Conditions are becoming more favorable for the development of
additional thunderstorms. Some storms may become strong to severe.

Winds in excess of 40 mph and pea size hail will be possible.

Strong, gusty winds will be capable of producing areas of blowing
dust with reduced visibilities.

Locations impacted include...
Phoenix, Mesa, Chandler, Glendale, Scottsdale, Gilbert, Tempe,
Peoria, Surprise, Avondale, Goodyear, Buckeye, Casa Grande, Apache
Junction, El Mirage, Florence, Fountain Hills, Paradise Valley,
Coolidge, and Tolleson.

This includes the following highways...
AZ Interstate 10 between mile markers 106 and 204.
AZ Interstate 17 between mile markers 195 and 220.
AZ Interstate 8 between mile markers 148 and 178.

If outdoors, consider seeking shelter inside a building.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

Alert: Extreme Heat Warning
Area(s): Buckeye/Avondale; South Mountain/Ahwatukee; Southeast Valley/Queen Creek
Effective: 2026-08-19 @ 12:49 pm -> 2026-08-20 @ 7:00 am
Onset: 2026-08-19 @ 12:49 pm -> 2026-08-23 @ 10:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Phoenix AZ on 2026-08-19 @ 12:49 pm
Headline: Extreme Heat Warning issued August 19 at 10:49AM MST until August 23 at 8:00PM MST by NWS Phoenix AZ
Description: * WHAT...For the Extreme Heat Warning, dangerously hot conditions.
Afternoon temperatures 109 to 112. Major Heat Risk. Overexposure
can cause heat cramps and heat exhaustion to develop and, without
intervention, can lead to heat stroke. For the Blowing Dust
Advisory, visibility between one-quarter and one mile in blowing
dust expected.

* WHERE...Buckeye/Avondale, South Mountain/Ahwatukee, and Southeast
Valley/Queen Creek.

* WHEN...For the Extreme Heat Warning, until 8 PM MST Sunday. For the
Blowing Dust Advisory, from 5 PM this afternoon to 10 PM MST this
evening.

* IMPACTS...Hazardous driving conditions due to reduced visibility.
Heat related illnesses increase significantly during extreme heat
events.

Alert: Extreme Heat Warning
Area(s): Parker Valley; Kofa; Yuma; Central La Paz; Southeast Yuma County; Gila River Valley; Imperial County Southwest; Imperial County Southeast; Imperial County West; Imperial Valley; Palo Verde Valley; Chuckwalla Valley
Effective: 2026-08-19 @ 12:49 pm -> 2026-08-20 @ 7:00 am
Onset: 2026-08-19 @ 12:49 pm -> 2026-08-23 @ 10:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Phoenix AZ on 2026-08-19 @ 12:49 pm
Headline: Extreme Heat Warning issued August 19 at 10:49AM MST until August 23 at 8:00PM MST by NWS Phoenix AZ
Description: * WHAT...Dangerously hot conditions. Afternoon temperatures 106 to
114. Major Heat Risk. Overexposure can cause heat cramps and heat
exhaustion to develop and, without intervention, can lead to heat
stroke.

* WHERE...Portions of southwest Arizona and southeast California.

* WHEN...Until 8 PM MST /8 PM PDT/ Sunday.

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

Alert: Extreme Heat Warning
Area(s): Tonopah Desert; Gila Bend; Northwest Pinal County; West Pinal County; Sonoran Desert Natl Monument
Effective: 2026-08-19 @ 12:49 pm -> 2026-08-20 @ 7:00 am
Onset: 2026-08-19 @ 12:49 pm -> 2026-08-23 @ 10:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Phoenix AZ on 2026-08-19 @ 12:49 pm
Headline: Extreme Heat Warning issued August 19 at 10:49AM MST until August 23 at 8:00PM MST by NWS Phoenix AZ
Description: * WHAT...For the Extreme Heat Warning, dangerously hot conditions.
Afternoon temperatures 106 to 114. Major Heat Risk. Overexposure
can cause heat cramps and heat exhaustion to develop and, without
intervention, can lead to heat stroke. For the Blowing Dust
Advisory, visibility between one-quarter and one mile in blowing
dust expected.

* WHERE...Gila Bend, Northwest Pinal County, Sonoran Desert Natl
Monument, Tonopah Desert, and West Pinal County.

* WHEN...For the Extreme Heat Warning, until 8 PM MST Sunday. For the
Blowing Dust Advisory, from 5 PM this afternoon to 10 PM MST this
evening.

* IMPACTS...Hazardous driving conditions due to reduced visibility.
Heat related illnesses increase significantly during extreme heat
events.

Alert: Extreme Heat Warning
Area(s): San Carlos
Effective: 2026-08-19 @ 12:49 pm -> 2026-08-20 @ 7:00 am
Onset: 2026-08-19 @ 12:49 pm -> 2026-08-23 @ 10:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Phoenix AZ on 2026-08-19 @ 12:49 pm
Headline: Extreme Heat Warning issued August 19 at 10:49AM MST until August 23 at 8:00PM MST by NWS Phoenix AZ
Description: * WHAT...Dangerously hot conditions. Afternoon temperatures 102 to
109. Extreme Heat Risk. Increase in heat related illnesses,
including heat cramps, heat exhaustion, and heat stroke. Heat
stroke can lead to death.

* WHERE...San Carlos.

* WHEN...Until 8 PM MST Sunday.

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

Alert: Extreme Heat Warning
Area(s): Aguila Valley; Cave Creek/New River; Fountain Hills/East Mesa; Apache Junction/Gold Canyon
Effective: 2026-08-19 @ 12:49 pm -> 2026-08-20 @ 7:00 am
Onset: 2026-08-19 @ 12:49 pm -> 2026-08-23 @ 10:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Phoenix AZ on 2026-08-19 @ 12:49 pm
Headline: Extreme Heat Warning issued August 19 at 10:49AM MST until August 23 at 8:00PM MST by NWS Phoenix AZ
Description: * WHAT...Dangerously hot conditions. Afternoon temperatures 103 to
111. Major Heat Risk. Overexposure can cause heat cramps and heat
exhaustion to develop and, without intervention, can lead to heat
stroke.

* WHERE...Aguila Valley, Apache Junction/Gold Canyon, Cave Creek/New
River, and Fountain Hills/East Mesa.

* WHEN...Until 8 PM MST Sunday.

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

Alert: Extreme Heat Warning
Area(s): Northwest Valley; Deer Valley; Central Phoenix; North Phoenix/Glendale; Scottsdale/Paradise Valley; East Valley
Effective: 2026-08-19 @ 12:49 pm -> 2026-08-20 @ 7:00 am
Onset: 2026-08-19 @ 12:49 pm -> 2026-08-23 @ 10:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Phoenix AZ on 2026-08-19 @ 12:49 pm
Headline: Extreme Heat Warning issued August 19 at 10:49AM MST until August 23 at 8:00PM MST by NWS Phoenix AZ
Description: * WHAT...Dangerously hot conditions. Afternoon temperatures 108 to
111. Major Heat Risk. Overexposure can cause heat cramps and heat
exhaustion to develop and, without intervention, can lead to heat
stroke.

* WHERE...Central Phoenix, Deer Valley, East Valley, North
Phoenix/Glendale, Northwest Valley, and Scottsdale/Paradise Valley.

* WHEN...Until 8 PM MST Sunday.

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

Alert: Air Quality Alert
Area(s): Pinal, AZ
Effective: 2026-08-19 @ 11:47 am -> 2026-08-20 @ 11:00 pm
Onset: 2026-08-19 @ 11:47 am
Severity: Unknown
Certainty: Unknown
Urgency: Unknown
Issued By: NWS Phoenix AZ on 2026-08-19 @ 11:47 am
Headline: Air Quality Alert issued August 19 at 9:47AM MST by NWS Phoenix AZ
Description: AQAPSR

The Arizona Department of Environmental Quality (ADEQ) has issued a
PM-10 High Pollution Advisory for Pinal County Today and Thursday.

An episode of strong and gusty winds is forecast to generate
widespread blowing dust that may result in local PM-10 concentrations
that pose a health risk. Adverse health effects increase as air
quality deteriorates.

Coarse particulate matter - also known as PM-10 - is an air
contaminant that can aggravate heart and lung disease conditions,
especially in older adults, children, and those with asthma. A
decrease in physical activity is recommended.

Consolidate your travel, stabilize loose soils, slow down or avoid
travel on dirt roads, reduce or eliminate fireplace use, and avoid
using gas-powered lawn equipment.

For details on this High Pollution Advisory, visit the ADEQ internet
site at www.azdeq.gov/forecast/WestPinal or call 602-771-2300.

Alert: Air Quality Alert
Area(s): Maricopa, AZ
Effective: 2026-08-19 @ 11:45 am -> 2026-08-20 @ 11:00 pm
Onset: 2026-08-19 @ 11:45 am
Severity: Unknown
Certainty: Unknown
Urgency: Unknown
Issued By: NWS Phoenix AZ on 2026-08-19 @ 11:45 am
Headline: Air Quality Alert issued August 19 at 9:45AM MST by NWS Phoenix AZ
Description: AQAPSR

The Arizona Department of Environmental Quality (ADEQ) has issued an
Ozone High Pollution Advisory for the Phoenix Metro Area Today and
Thursday.

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.

Alert: Extreme Heat Warning
Area(s): Lake Havasu and Fort Mohave; Lake Mead - AZ side; Lake Mohave - AZ side; Hualapai Mountains; Northwest Deserts; Death Valley National Park; Eastern Mojave Desert, Including the Mojave National Preserve; Morongo Basin; Cadiz Basin; San Bernardino County-Upper Colorado River Valley; Northeast Clark County; Western Clark and Southern Nye County; Las Vegas Valley; Southern Clark County; Lake Mead - NV side; Lake Mohave - NV side
Effective: 2026-08-19 @ 6:11 am -> 2026-08-20 @ 7:00 am
Onset: 2026-08-19 @ 6:11 am -> 2026-08-21 @ 10:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Las Vegas NV on 2026-08-19 @ 6:11 am
Headline: Extreme Heat Warning issued August 19 at 4:11AM PDT until August 21 at 8:00PM PDT by NWS Las Vegas NV
Description: * WHAT...Dangerously hot conditions with temperatures up to 115 to
118 degrees expected through Death Valley and the lower Colorado
River Valley, with highs between 107 to 110 degrees elsewhere.

* WHERE...Portions of northwest Arizona, southeast California, and
southern Nevada.

* WHEN...Until 8 PM PDT /8 PM MST/ Friday.

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

Alert: Extreme Heat Warning
Area(s): Grand Canyon Country
Effective: 2026-08-18 @ 3:40 pm -> 2026-08-20 @ 10:00 pm
Onset: 2026-08-18 @ 3:40 pm -> 2026-08-20 @ 10:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Flagstaff AZ on 2026-08-18 @ 3:40 pm
Headline: Extreme Heat Warning issued August 18 at 1:40PM MST until August 20 at 8:00PM MST by NWS Flagstaff AZ
Description: * WHAT...Dangerously hot conditions expected below 4000 feet, with
daytime temperatures ranging from 96 to 102 degrees at Havasupai
Gardens, and 107 to 111 degrees at Phantom Ranch.

* WHERE...Lower elevations of the Grand Canyon.

* WHEN...Until 8 PM MST Thursday.

* IMPACTS...Most individuals will be at risk for heat-related
illnesses without effective cooling or adequate hydration,
especially with prolonged outdoor exposure.