Portugal has recorded its hottest May in at least 90 years, with temperatures soaring past previous highs by a margin that has stunned climatologists. The national weather service, IPMA, confirmed thermometers hit 36.9°C in the central town of Mora, eclipsing the prior May record by more than two degrees. This is not an anomaly but a signal. The Iberian Peninsula is now a laboratory for life at 2°C of warming.
The heat arrived in late May, parked over the Atlantic coast by a high-pressure system that refused to move. The same system has driven wildfires in Spain and water shortages across southern France. The physics is simple. A warmer atmosphere holds more moisture, but it also demands more evaporation. Soils dry faster. When the heat comes, it lands on parched ground and bakes it harder.
We are watching the breakdown of a seasonal norm. May used to be a month of mild, flowering spring. Now it is a month of heatwaves. Portugal’s previous May record of 34.5°C was set in 2018. That year also saw catastrophic fires. The trend is clear. Every record is a stepping stone to a hotter baseline.
The cause is not in dispute. The global average temperature has risen 1.2°C since the industrial revolution. Europe is warming twice as fast. The Mediterranean basin is a hotspot. Human activity has loaded the atmosphere with carbon dioxide, methane, and nitrous oxide. These gases trap heat. The heat accumulates. The records fall.
This has real consequences. Portuguese vineyards are seeing harvests move weeks earlier. Olive groves are stressed. The cork industry, a pillar of the economy, faces an uncertain future. But the most immediate danger is human health. Heat is the silent killer. It strains hearts and kidneys. It exacerbates respiratory diseases. In 2003, a European heatwave killed 70,000 people. The infrastructure for cooling is still inadequate.
There are technological solutions. We can build more efficient air conditioning powered by solar energy. We can redesign cities to include shade corridors and green roofs. We can shift agricultural practices to drought-resistant crops. But these are adaptations, not solutions. The root cause remains emissions.
The tragedy is that we have known this for decades. The first IPCC report in 1990 laid out the trajectory. We have delayed. Now we are paying the price in shattered thermometers and burning hillsides.
The question is whether we can still change course. The answer is yes, but only with rapid, aggressive decarbonisation. That means retiring fossil fuel infrastructure before the end of its natural life. That means building renewables at a pace that breaks economic models. That means carbon removal technologies, both natural and engineered.
Portugal has already shown leadership. In 2021, it generated 60% of its electricity from renewables. But the transport sector remains heavily dependent on oil. Homes still burn natural gas for heating. The gap between electricity generation and total energy consumption is the challenge.
The planet does not negotiate. It responds to physics. Every tonne of carbon dioxide we emit adds to the warming. The May record in Portugal is a data point in a relentless curve. We must either bend that curve or accept a future where records like this become the new May normal.
The science is settled. The choice is ours.
