The planet is not returning to its old temperature balance. The year 2025 was the third warmest globally since the preindustrial era, while the past 11 years were among the hottest ever recorded. This is no longer a single record. It is a new structure of climate.
Global average temperature matters for science, but people do not live in a global average. They live in Kryvyi Rih, Shanghai, Moscow, Lagos, Buenos Aires, Honolulu or Salt Lake City. That is why the most persuasive evidence is not an abstract planetary graph, but a map of cities where heat has entered daily life.
In 2025, thousands of cities around the world recorded their highest average annual temperatures since at least 1950. More than 1,200 cities set their own heat records. Cities with their coldest year nearly disappeared: among major urban centers, Manvi in India stood out as the rare exception.
According to Daycom’s assessment, the central meaning of this data is that the climate crisis has become local. It is no longer described only by ocean temperature or a global anomaly. It can be seen in a specific city, in a specific January, in a specific rhythm of hot and cold months.
Kryvyi Rih offers a revealing Ukrainian example. In 2025, the city’s average temperature was about 11.8 degrees Celsius, or 53.3 degrees Fahrenheit. It was the city’s third-warmest year since 1950. Temperatures there are rising at a rate of about 0.6 degrees Fahrenheit per decade.
That figure may seem modest, but this is how climate change works: not as a single sudden leap, but as a slow shift in the baseline. What once looked like a warm deviation gradually becomes the new normal. Then that new normal shifts higher again.
In Kryvyi Rih, nine months of 2025 were warmer than normal. January was especially warm, while February was notably colder than average. This matters: warming does not eliminate cold episodes. It changes the background against which such episodes occur, making them increasingly rare.
That is why climate cannot be judged by one cold week or one snowy winter. Record-hot years are made up of months that may differ sharply from one another. But when most months are warmer than normal and cold records almost disappear, the system is already operating differently.
In the past, cold records used to be broken frequently. Now they are becoming rare. Heat records, by contrast, are broken regularly, and that is one of the clearest signals of long-term warming. Climate statistics are no longer balanced between symmetrical extremes. They have shifted in one direction.
This has direct consequences for weather. A warmer atmosphere holds more moisture: about 7 percent more for every 1 degree Celsius of warming. That increases the risk of more intense rainfall and severe flooding. A similar relationship applies to heat waves and droughts: a warmer background makes extremes harsher.
Climate change does not necessarily create every individual flood, fire or heat wave from nothing. But it intensifies them. It acts as a threat multiplier, adding more energy, more moisture, more evaporation, longer heat periods and deeper stress for ecosystems to familiar natural risks.
Several forces shaped the 2025 picture. The main one was emissions of carbon dioxide, methane and other greenhouse gases. Warm oceans added to it, storing and returning enormous amounts of energy to the atmosphere. Oceans often make global warming persistent rather than accidental.
Another factor looks paradoxical. The reduction of sulfate aerosols in the air has made the atmosphere cleaner, but it has also removed some of the particles that previously reflected sunlight and slightly cooled the surface. Cleaner air is a victory for public health, but it also allows more solar heat to reach land and ocean.
India partly departed from the global pattern because of the lingering influence of La Niña in the Pacific, which brought more rainfall and cooler conditions to some regions. But such exceptions do not change the broader trend. They show only that global warming appears unevenly, through local circulation, monsoons, oceans and seasonal shifts.
The greatest danger lies not only in temperature itself. Warmer years mean stronger storms, higher fire risk, greater pressure on water, crops, power grids, transport and public health. Cities become laboratories of this risk because they concentrate people, concrete, infrastructure and inequality.
Urban climate is especially vulnerable. Asphalt, rooftops, industrial zones and dense construction store heat. Green spaces and water can soften it. That is why heat is distributed unevenly even inside a single city: poorer districts often have less shade, worse housing and weaker access to cooling.
Local data changes adaptation policy. When a city sees its own temperature trajectory since 1950, it can no longer describe climate as a distant global problem. It has to plan shade, water, green corridors, cooling centers, new building standards and protection for vulnerable people.
Kryvyi Rih matters in this sense not only as a point on Ukraine’s map. It is an industrial city with a heavy legacy, dense infrastructure and high dependence on energy, water and working schedules. For such a city, warming means not only discomfort, but changing conditions for labor, health care and urban planning.
If summers become longer and hotter, outdoor work needs different schedules. If downpours become more intense, storm drainage must change. If winters grow milder but cold episodes do not disappear entirely, energy systems must be ready for both soft seasons and short peaks of demand.
The global forecast is also becoming harsher. Long-term warming is likely to exceed the 1.5-degree Celsius threshold by 2029. That is roughly a decade earlier than expected at the 2015 Paris climate summit, where more than 190 countries agreed on the goal of limiting the most dangerous risks.
Crossing that threshold does not mean the immediate end of the world. But it does mean a narrowing of the safe corridor. Every additional tenth of a degree increases the likelihood of extreme heat, droughts, wildfires, floods, biodiversity loss and social pressure on countries that are already poorly adapted.
The problem is intensified by the fact that greenhouse gas emissions are still rising, while natural carbon sinks — oceans, forests and soils — are becoming less able to absorb them. The system that once partly softened human emissions is losing efficiency. That makes emissions cuts not a political slogan, but a physical necessity.
The only way to slow overall warming and the extreme weather linked to it is to reduce greenhouse gas emissions. Adaptation is necessary because change is already underway. But without emissions cuts, adaptation becomes an endless race against an accelerating crisis.
The methodology behind this kind of analysis has universal significance. It allows nearly 60,000 cities and towns to be compared through a single logic, using a global grid of land-surface temperatures from 1950 to the present. This is not a replacement for local weather stations, but a different scale of climate measurement.
For each city, a representative point is identified within its boundaries, after which the temperature series of the corresponding climate grid cell is analyzed. If a city is coastal or island-based and the point falls on water, the data is matched with the nearest valid land cells. This makes the comparison global and systematic.
The limits are important. Temperatures in such a grid may be slightly lower or higher than readings from a specific thermometer at an airport or in a city center. A single climate grid cell averages a large area, including parks, buildings, industrial zones, fields or slopes. A weather station, by contrast, measures one precise point.
But for trend analysis, this is not a weakness. It is a strength. A local thermometer can be shaped by microclimate, asphalt, elevation or placement. Gridded data shows the broader climate change around a city. Absolute numbers may differ, but the direction and strength of the trend remain reliable.
That is why the methodology is universal: it does not ask whether a city is large or small, rich or poor, coastal or inland. It gives a common language for comparing climate change. And that language points to a simple conclusion: 2025 was not an exception, but another proof that a warmer planet is already living inside our cities.
