A new website lets Madrid Metro passengers report heat issues in real time. Data shows Line 1 is worst affected. Authorities promise urgent upgrades, but users remain frustrated.
Madrid’s Metro is under scrutiny after a surge of passenger complaints about extreme heat and malfunctioning air conditioning, especially on Line 1. A recently launched citizen platform, Termo de Madrid, now collects daily reports from commuters, revealing widespread discomfort and technical failures across the network. The initiative, created by Nacho González, aims to document the scale of the problem through user-submitted data, highlighting the persistent lack of effective climate control in the city’s busiest and oldest metro line.
Termo de Madrid aggregates passenger experiences into a unique index, scoring each incident from 0 (“fresco”) to 100 (“infierno”) based on perceived heat, number of reports, and estimated fleet coverage. The platform’s data shows that Line 1 consistently records the highest proportion of carriages with climate issues, followed by Line 5. The most critical periods are around 15:00, coinciding with the end of intensive work shifts, and early mornings at 7:00. In the past four days, the number of incidents has spiked, with Friday morning alone seeing 10 out of 25 reports classified as “infierno.”
The methodology behind the index prioritizes recent reports, using an exponential decay system that halves the weight of each entry every three days. It also adjusts for the number of unique trains affected, ensuring that repeated complaints about the same carriage do not distort the results. A confidence indicator, ranging from low to high, reflects the statistical reliability of the data based on the volume and consistency of reports. Confidence is considered high only when at least ten reports are received and 70% agree on the conditions.
Jorge Nacarino, president of the Federación Regional de Asociaciones Vecinales de Madrid (FRAVM), points to delayed maintenance contracts as a key factor behind the crisis, particularly on Lines 1 and 5. He criticizes the regional government for a lack of transparency and slow response, arguing that users and social groups have been forced to raise awareness through social media. Metro de Madrid has responded by announcing increased maintenance checks, installation of industrial fans on platforms, and a €3.5 million investment to upgrade air conditioning in 93 trains serving the most affected lines. Regional officials acknowledge the discomfort caused by high temperatures and insist that efforts are underway to improve passenger comfort.
While authorities highlight ongoing improvements, many residents remain skeptical, especially as the summer heat coincides with service disruptions due to construction and maintenance. The situation is further complicated by simultaneous works on Madrid’s Cercanías network, which some see as evidence that passenger needs are not being prioritized in public transport planning. This tension echoes broader concerns about infrastructure management in the region, as seen in other recent local controversies such as the cancellation of public events due to safety risks, detailed in this report on Madrid municipalities cancelling eclipse events.
For context, Madrid Metro is one of Europe’s largest urban rail systems, serving nearly 197 million passengers annually on Lines 1 and 5 alone. The network’s age and heavy usage make climate control a persistent challenge, especially during peak summer months. The current crisis has reignited debate over investment priorities, transparency, and the effectiveness of public communication. As the city faces another hot August, the pressure is on for authorities to deliver tangible improvements and restore commuter confidence in the capital’s vital transport system.
