The article points to hotter summer weather (attributed to climate change) as the driver of this "elongating" of peak tourist season. No doubt that is a factor, but they fail to mention the other, dramatic change in the "tourism climate" which might be an even bigger factor: the explosive growth of the worldwide tourism industry. There are just more people traveling. That is a trend that has been rising even faster than mid-summer temperatures in Rome and it's nothing new -- tourist numbers have been going up, up, up for years (decades). It's been most dramatic and harder to ignore this summer in Europe (after the relative absence of tourists during the depths of the pandemic), but it is a long-term trend that has been very obvious for decades -- and not just in places that get hot in July and August.
Those customers gotta "go" somewhere -- so if a place (eg Venice, Prague, Barcelona, etc.) is effectively at -- or over -- capacity during the "traditional" busy summer months, time-shifting happens. This is nothing new, and savvy travelers have long looked to what we used to call "shoulder season" to find fewer crowds, lower prices, and yes, cooler, more comfortable weather -- for an overall better experience in popular places. And even in places you may never have heard of.
As someone who does not enjoy crowded places, I've sought out crowd-free (or at least low-crowd) places for a long time. Finding those places gets more challenging every year. I don't enjoy excessive heat either, so I tend to favor places that don't get super-hot. For me, going to Rome (or fer cryin' out loud, Sicily!) in August is just not something I would ever contemplate (and yes, I know, some people have constraints on when they can go away, so for them it may be August or stay home).
I keep wondering if this summer's tourism meltdowns and unprecedented crowds across Europe, like intense heat waves, are another sign of "the new normal" we will have to get used to, or a one-time "perfect storm" triggered by a combinations of pent-up pandemic tourism demand plus pandemic-induced labor (and supply-chain) shortages. Most observers keep referring to it (the crowds and meltdowns) as a short-term phenomenon that will pass as everything gets back to (something like) normal. I sincerely hope it passes, but I worry this is how it's going to be going forward.
Worth noting: the current spike in tourism that has nearly brought down many systems across Europe seems to be driven primarily by North Americans and Europeans. But there are plenty of traditional tourist customers still stuck at home. Tourists from China, once highly visible everywhere (but especially at the top tourism magnets across Europe), are still not traveling in large numbers. Russians are traveling some, but not like they used to, and they're mostly going to places that are not part of the pushback against their invasion of Ukraine. Plenty of other groups of people who were major contributors to the industry's success pre-pandemic are still largely absent. Once all those people start packing their bags again and hopping on cheap flights...I wonder if the tourist crowds we have witnessed this summer will continue and even get worse. To many people, the pandemic has driven home the meme of "you only live once" so you might as well get out there. I'll be keenly interested to see how things go next summer.
Me, I will continue to seek out places that are not world-famous tourist magnets, in less crowded but still fascinating (and cooler) locations. You can have Rome in August, I'm doing my part to mitigate the crowding there. (Tip: You can get good gelato in lots of places around the world now).