Coincidence? Earth Day 2024 comes a day after Phoenix hits 100 degrees

On Sunday, Phoenicians were handed a 100-degree day for the first time this year when the thermometer at Sky Harbor International Airport hit the century mark at 3:10 p.m.

Even though 100 degrees went away quickly (it was Sunday’s high) — it got here earlier than usual: The average day for Phoenix to hit triple digits is May 2.

The earliest the city has ever hit that number (since records started being kept, anyway) was on March 26, 1988.

While “a hundy” visited Phoenix early-ish, it came after a cooler, wetter winter than usual. We didn’t reach 90 degrees for the first time until April 11, 12 days later than the historical average.

So, on Earth Day, I think it’s worth discussing if our kinda-sorta early 100 degrees is a sign of anthropomorphic global warming.

Maybe. But there’s no doubt in my mind that humans are playing a part in making Phoenix hotter — and that’s happened simply by humans making Phoenix (and its environs) bigger.

I got a chuckle out of some of the comments accompanying a KTAR News Facebook post on Phoenix hitting 100 degrees.

A man named Steve asked, “Are we playing the ‘airport game’ again? …it’s so stupid because everybody knows it’s an extra 5 degrees there [the airport].”

Steve and a couple of other people were doing something that I first noticed last year. 

During a summer that featured a record run of 110-or-higher temperatures — coupled with a wimpy monsoon (which delivered little-to-no rain at Sky Harbor), some people accused the media and the National Weather Service of perpetuating what they consider to be a hoax: global warming.

Their biggest gripe was that the National Weather Service’s official Phoenix thermometer (and rain gauge) are located at Phoenix’s main airport. A lady named Tanya said in Sunday’s Facebook convo that KTAR should “stop reporting fake news. It did not hit 100 degrees unless you were surrounded by concrete.”

She’s probably right (about the concrete) but that’s why I thought it was funny that a guy named Jeffrey tried to prove the point that airport temps are hotter than reality by listing some high temps from around the Valley that were 2-5 degrees below 100 — and most of the temps were recorded at airports. 

Since those temperatures Jeffrey posted are in suburban areas, they are going to be lower because (as Tanya pointed out) they are surrounded by less concrete than an urban area would be — and Sky Harbor is one of the most urban airports in the U.S., just a couple miles east of downtown Phoenix. Compare that to Denver International — which is located so far east of its titular city that it’s practically in Kansas.

All the concrete, blacktop and roof tiles that have gone into building metro Phoenix creates one of the most pronounced urban heat island effects anywhere. Those materials absorb and retain the sun’s energy overnight, making it that much easier to get back to a climate condition known as “hotter’n Hades” the next day.  

According to the Arizona State Climate Office, “Phoenix has one of the largest urban heat island magnitudes in the world [the difference between the urban air temperature and the rural air temperature in a geographical area], with up to a 10-14 degree difference between Phoenix Sky Harbor Airport and Wickenburg, Queen Creek, Casa Grande, or [the city of] Maricopa.”

That last part seems like it was almost written for Steve, Jeffrey and Tanya.

The only way to combat the urban heat island effect is to make our urban areas a little more rural by doing things like planting trees.

Or we can escape the heat island by doing what Facebook commenter Dave did: “Having left there, in November, after 40 years, I find it funny that people would squabble over a couple of degrees. ‘It wasn’t 100, it was 96… I don’t miss it at all.”

I wouldn’t miss the heat either — but I’d miss too many other (cool) things to actually be able to join Dave — and vote myself off the island known as “Urban Heat.” 

Follow @JimSharpe