The Second Climate Monitoring Report for Rome, produced by CMCC, shows how average temperatures, heatwaves, extremely hot days, and tropical nights are now part of an increasingly evident trend, with recent years consistently ranking among the warmest on record.

Rome, 2 July 2026 – The intense heat affecting Italy, and particularly in large cities, is an increasingly frequent and measurable signal of a changing climate. In recent years, this has brought higher average temperatures, more episodes of extreme heat, a growing number of tropical nights, and increasing pressure on urban systems, from public health to energy demand.

This is the picture that emerges from the Second Climate Monitoring Report for Rome, produced by CMCC and presented alongside the city’s Heat Plan. The report provides a high-resolution analysis of the urban climate and delivers scientific data to support Rome’s Climate Adaptation Strategy.

The case of Rome is emblematic. According to CMCC data, 2025 ranks among the warmest years since 1991: annual average temperatures exceeded the 1991–2020 climate baseline, with a particularly marked anomaly in June, when average temperatures were about 4°C higher than the reference period for that month. Recent years confirm a clear trend: 2022, 2023, 2024, and 2025 all rank among the five warmest years on record.

Heat and thermal discomfort are increasing

Beyond average temperatures, indicators describing extreme heat and thermal stress in urban areas are also on the rise. In 2025, Rome recorded over 40 extremely hot days – defined as days with maximum temperatures above 35°C – ranking fourth since 1991 in terms of number of such days. The same year also ranks among the top five in the historical series for number of heatwaves, duration of hot periods, cooling degree days, and tropical nights.

Tropical nights are one of the most relevant indicators for understanding the impact of heat on daily life and health: they refer to nights when minimum temperatures do not fall below 20°C, limiting physiological recovery after very hot days. In Rome, 101 tropical nights were recorded in 2025, compared to an average of 76 during 1991–2020. Energy demand also reflects this transformation with a strong increase in summer due to cooling needs.

“Heatwaves observed today and in recent years can no longer be interpreted as exceptional and isolated events, but as signals of a structural climate transformation that has already been affecting the city for several years,” explains CMCC researcher Paola Mercogliano, director of the research group working on climate reports for Rome. “In the coming years,” Mercogliano continues, “this transformation could become even more significant. For a complex urban system like Rome, the value of climate monitoring lies precisely in this: transforming high-resolution climate data and information into actionable insights for planning, prevention, and decision-making by public and private actors, and the community at large. The Roma Climate Hub platform makes it possible to read climate change across the territory, even at neighbourhood level, providing updated indicators, maps, and scenarios that help identify the most exposed areas, assess intervention priorities, and support the implementation of Rome’s Climate Adaptation Strategy. Continuously and increasingly accurately measuring the urban climate means supporting the development of more targeted, transparent, and verifiable adaptation policies over time.”

The climate monitoring developed by CMCC for Rome uses ultra-high-resolution datasets to provide robust and reliable territorial information, useful for urban planning and evaluating adaptation measures. Priorities identified in Rome’s Climate Adaptation Strategy include adapting neighbourhoods to rising temperatures, managing risks related to intense rainfall and flooding, ensuring water supply security, and protecting the coastline from the impacts of coastal erosion and sea level rise.

Looking ahead, analysed climate scenarios indicate a further increase in temperatures and heat indicators for Rome. Compared to 1991–2020, average daily temperatures could rise between 1.2°C and 1.8°C depending on whether high- or low-ambition climate policy scenarios are considered. Tropical nights could increase by 26 to 36 days, while the number of summer heatwaves could increase by two and a half times or triple compared to the reference period.

The Second Climate Monitoring Report for Rome Capital therefore confirms the need to interpret extreme heat events not as episodic emergencies, but as part of structural change requiring updated scientific tools, targeted adaptation policies, and clear communication to citizens, institutions, and decision-makers.

The Second Climate Monitoring Report for Rome is available at this link (PDF).
For more information on the First Climate Monitoring Report for Rome Capital, click here.
Watch the CMCC video on the Roma Climate Hub.

Access the Dataclime platform to consult and download data and maps on climate change indicators for Italy (free registration required).