June's brutal heatwaves in Western Europe did more than buckle power grids and close schools. According to the latest World Tourism Barometer from UN Tourism, they helped drive international arrivals down three per cent worldwide that month – with Western Europe seeing an even steeper six per cent decline.

The numbers tell a story of a season under strain. Summer 2025 brought record temperatures across the continent, and the WHO's director-general Tedros Adhanom Ghebreyesus didn't mince words in June, noting that Europe is warming at twice the global average, with around 150 million people living under extreme heat and hundreds of deaths recorded. For a region that sells itself on long, reliable summers, that's a genuine commercial problem as well as a humanitarian one.

It wasn't just the heat. Geopolitics weighed on the half-year figures too. Some 690 million people travelled internationally between January and June, a marginal year-on-year increase of 0.4 per cent – growth, but barely. The Middle East recorded a 22 per cent drop over the same period as conflict and air-traffic disruption took their toll, though things eased after a ceasefire was announced. Oceania took a hit in June as well, down six per cent, after Typhoon Sinlaku. UN Tourism's secretary-general Shaikha Al Nuwais summed it up bluntly: growth hasn't stopped, but it's fragile.

Here's the twist, though: Europe still had its busiest summer in the skies ever. Eurocontrol figures show an average of 35,959 daily flights between 1 June and 31 August, up 2.4 per cent on the previous year, despite the Middle East disruption. On 10 July the network hit an all-time peak of 37,640 flights in a single day. So while some holidaymakers apparently shifted or shelved trips during the hottest weeks, plenty more still flew – and planes kept packing into European airspace at record density.

Looking ahead, UN Tourism expects international arrivals to grow one to two per cent globally in 2026, with the caveat that geopolitical volatility, oil prices and inflation could all derail that. Its other prediction is telling: travellers will increasingly chase value for money and stay closer to home or within their own borders rather than absorb the cost of long-haul trips.

For anyone planning a European holiday, the practical takeaway is straightforward. June is no longer a safe bet as a mild shoulder month – it's now regularly one of the hottest of the year, and crowds thin when the mercury spikes, which cuts both ways. Consider travelling in late spring or September instead, book city breaks with real shade, water and air-conditioning, and treat peak-summer heat as something to plan around rather than endure. If you do fly in summer, expect crowded skies and build buffer time into connections. The demand is clearly still there; it's the timing and the comfort levels that are changing.