Why Phoenix Is Experiencing More Extreme Heat Days Now

Baby, it’s hot outside. Have you ever noticed how people compare heat to two things? Hell or Phoenix in summer.

If you’ve lived in Arizona for a while, you’ve probably noticed that summers feel hotter than ever, and nights don’t cool off like they used to. It’s not your imagination; science supports it.

Statistical data shows that as the Valley has grown, so has the heat. When I first moved to Arizona many decades ago, there was still a lot of farmland spread across Maricopa County.

Now, these areas have been replaced by urbanization, and they’re now packed with asphalt, rooftops, and concrete. All of these things trap heat, and the process continues long after sunset.

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What Is the Urban Heat Island Effect?

If you live in Phoenix or nearby, you’re now living in an Urban Heat Island.

The “urban heat island” effect means that cities tend to be warmer than the surrounding rural areas. In Phoenix, pavement and buildings absorb daytime heat and slowly release it at night. This prevents the air from cooling, according to researchers at ASU.

In Phoenix, you really feel this effect. Studies show that the city's temperature can be 10–14°F higher than open desert or rural areas on summer nights.

READ: 3 Reasons Phoenix Shouldn't Exist

Rising Temperatures Over Time

Urban growth over the last 50–100 years has significantly increased Phoenix's heat levels.

Research shows nighttime minimum temperatures have risen steadily. Again, this is primarily because the city no longer cools off after sunset the way it once did.

At Sky Harbor Airport, urbanization has increased nighttime temperatures by about 9°F and average daily temperatures by more than 5.6°F compared with earlier decades.

The extreme temperatures are so hot that they routinely make national news. Extreme heat days that hit the mercury over 110°F have increased in the past 50 years. The data from ARGIS.com supports this.

What the Future Holds

If you can’t stand the heat, the news isn’t good. Data suggests Phoenix will continue to get hotter over the next few years. The population is ballooning, which means more urban development and the construction of even more heat-trapping surfaces.

And that’s not even taking into account that climate change is expected to intensify extreme heat events.

READ: The Science Behind Phoenix’s Relentless Summer Heat

Experts say that if we don’t plant more trees, add shade, or use cooler building materials, we’ll end up with hotter nights and longer heat waves as just part of everyday life in the Valley.

And that’ll make Phoenix even hotter than Hades.

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