Florida heat without Florida air conditioning? Europe is finding out

Imagine a July afternoon in Florida, and the cold air is simply not there.

Not because the AC broke. Not because the power went out. But because it was never installed.

Imagine the school without it. The office. The hospital. The train. The apartment building. The museum. Imagine daily life trying to continue through a Florida Summer in rooms that were never designed to be cooled.

This is not a mere thought experiment in much of Europe. During the recent heat wave, power systems, railways and public buildings all came under stress. Train operators in several countries faced delays as heat put tracks and onboard systems under strain. Public buildings struggled to keep indoor temperatures under control. In old apartment blocks, the heat that entered during the day stayed long after sunset.

Europe has many of the things Americans associate with a highly developed society: high-speed trains, luxury cars, old universities, modern hospitals, busy airports and factories that still make machinery sold around the world. It also has millions of homes, schools and offices built for summers that no longer behave the way they used to.

A Floridian knows heat through escape from it. The house is cooled before breakfast. The car cools after a few minutes. The grocery store is cold. The office is often too cold. Florida Summer is lived in short crossings between air-conditioned spaces.

In the Sunshine State, 96% of households use air conditioning, according to the U.S. Energy Information Administration. Across Europe, the International Energy Agency puts air-conditioning ownership at about 20%.

Europe’s limited ability to cool itself has caused problems over the past several days. In France, EDF, the state-controlled utility that runs the country’s nuclear fleet, reduced output by 4.1 gigawatts at one point, about 7% of national power demand. The restrictions affected reactors on the Rhône, the Seine and the Garonne. One reactor at Golfech went offline.

The reason was not a broken plant. Nuclear reactors use river water for cooling and return warmer water to the river. French rules limit those discharges when rivers are already too warm. With temperatures above 104 degrees in parts of Western Europe, the rivers became a limit on the plants beside them.

France usually sells surplus electricity to neighboring countries. During the heat wave, afternoon exports fell to about 3 gigawatts, down from 10 to 12 gigawatts at the same point the previous week. Spot power prices in France and Germany reached their highest level since January 2025 as cooling demand rose and wind output weakened.

The heat also reached the railways. Germany recorded a preliminary national high of about 106 degrees near Saarbrücken, close to the French border. Deutsche Bahn allowed passengers to cancel long-distance trips free of charge into the following week. National Express suspended some trains in North Rhine-Westphalia as a precaution. Near Hamburg, heat split asphalt on one of Germany’s busiest motorways and closed part of a main lane.

Inside homes and public buildings, the problem is quieter. A fifth-floor apartment in Paris, Milan or Berlin can hold heat for days. The old European routine depended on cooler nights: open the windows after sunset, let the walls release heat, begin again in the morning. When the night stays warm, the routine no longer works.

Air conditioning is spreading, but Europe is adding it late. The European Commission has said the number of room air conditioners in the European Union rose from 57 million in 2020 to 104 million expected by 2030. Many of those units will be installed in buildings that were not designed for them.

Germany shows why the next stage will be even harder. The country shut down its last three nuclear power plants in April 2023. It expanded wind and solar power and pushed more of the economy toward electricity, from cars to heating systems to industry. Now, hotter Summers are increasing demand for air conditioners, which many German households did not have a few years ago.

Germany has already seen what happens when the weather does not cooperate. In late 2024, periods of little wind and little sun — known in German as Dunkelflaute — pushed wholesale electricity prices sharply higher. Regulators later examined whether power companies had held back supply, but the immediate problem was weather: wind and solar plants were producing little, and other sources had to fill the gap.

In May, heat brought a Summer version of the same pressure. German day-ahead electricity prices jumped 29% as cooling demand rose while wind output was expected to fall sharply. Wind generation was forecast to drop from 14.1 gigawatts to 4.4 gigawatts for the next day. Gas and coal plants had to cover a larger share of the load.

Air conditioning is therefore arriving in Germany as another electrical demand on a system already under strain. Solar power helps during hot afternoons. Low wind still pushes the system back toward gas and coal. Grid expansion remains slow. Electricity prices are already a burden for households and industry.

And the next demand is in line. The IEA expects global electricity use by AI data centers to roughly double by 2030.

Germany is already Europe’s largest data-center market, and its government wants more digital infrastructure. All while Berlin has not finished figuring out how to power the air conditioners it never thought it needed.