Extended Extreme Heat Warning in Effect Across Maricopa County
The National Weather Service has extended its Extreme Heat Warning for Phoenix and surrounding areas through Friday evening, as temperatures soar well above seasonal averages across Maricopa County.
Dangerously High Temperatures Expected Through the Week
As of Tuesday morning, the National Weather Service (NWS) reported temperatures in the Phoenix metro area reaching 111°F, with similar highs forecast through Friday, June 21. The warning covers key urban centers including Phoenix, Scottsdale, Tempe, Mesa, Glendale, Buckeye, Cave Creek, and Central Phoenix.
The heatwave has prompted warnings from local health officials urging residents to avoid prolonged outdoor activity, stay hydrated, and check on vulnerable populations. The NWS notes that nighttime lows will also remain elevated—providing little relief from the daytime heat.
“This is a prolonged heat event with increased potential for heat-related illness,” the NWS stated in its advisory for Maricopa County. “Take precautions, especially for the elderly, children, and pets.”
Heat Risk Level 4: Major to Extreme Health Concerns
According to the Arizona Department of Health Services (ADHS), this week’s conditions fall under HeatRisk Level 4, indicating major to extreme health risk for those exposed. In 2023, Phoenix recorded 645 heat-related deaths, a 50% increase from the previous year. Officials are urging residents not to underestimate the risk of repeated exposure to high temperatures.
The Maricopa County Public Health Department has activated a Heat Relief Network, with dozens of cooling centers now open throughout the Valley. Locations include libraries, senior centers, and non-profit facilities where individuals can access cold water, air conditioning, and respite from the heat.
Cooling Center Resources and Heat Relief Map
Residents can locate their nearest cooling station using the Maricopa Association of Governments (MAG) Heat Relief Network map. Many centers are open from 9 a.m. to 5 p.m., with extended hours in areas of greatest need. Bottled water distribution points and hydration stations are also set up at select Valley Metro light rail stops and shelters.
To find a cooling center:
- Visit: www.heataz.org
- Or call: 2-1-1 Arizona (free resource hotline)
Public Safety and Transportation Advisory
The Arizona Department of Transportation (ADOT) has issued reminders for drivers to avoid vehicle breakdowns by checking coolant levels, battery status, and tire inflation before travel. Roadside assistance calls increase significantly during excessive heat periods.
Valley Metro officials say public transit remains operational, but high temperatures can delay bus service or limit rail efficiency. Riders should bring water and wear sun protection when traveling during midday hours.
Urban Heat Island Effect Magnifies Risks
Downtown Phoenix and other urban corridors are especially susceptible to the Urban Heat Island Effect, where paved surfaces and reduced greenery cause temperatures to spike above surrounding areas by 7–10°F. Studies from ASU’s School of Geographical Sciences have shown that extreme heat events disproportionately affect low-income neighborhoods with limited shade and tree cover.
City officials are continuing long-term efforts to expand cool corridors, invest in reflective pavement, and plant shade trees—particularly in South Phoenix, Maryvale, and Sunnyslope areas.
Tips to Stay Safe During the Heat Wave
- Hydrate: Drink water frequently, even if not thirsty.
- Avoid Peak Hours: Stay indoors between 10 a.m. and 4 p.m..
- Never leave pets or children in vehicles.
- Use AC: Seek air-conditioned environments.
- Check on elderly neighbors and those without access to cooling.
Looking Ahead
Temperatures are expected to gradually ease beginning Saturday, June 22, though Phoenix will likely remain above 105°F into next week. Meteorologists warn that additional heat waves are likely as summer continues.
If you or someone you know needs heat assistance, dial 2-1-1 or visit a designated cooling center.