All cars are air-conditioned. Traveling between two cities, you can take in the view through the large windows, and enjoy comfort you won't find in air travel. Most trains also carry a cafe, in which you can order hot and cold snacks, sandwiches, beer and alcoholic drinks, and a wide range of non-alcoholic beverages.

In most developed countries, the vast majority of modern passenger trains are fully air-conditioned, but there are notable regional exceptions. In Japan (Shinkansen), China (CRH), and the United States (Amtrak), climate control is a standard feature on all intercity and regional routes. In Europe, most high-speed trains (TGV, ICE, Eurostar) are exceptionally well-cooled. However, some older commuter networks still struggle. A famous example is the London Underground; while newer "S-Stock" trains (Circle, District, Elizabeth lines) are air-conditioned, the "deep tube" lines (Central, Northern, Victoria) are not, because the 19th-century tunnels are too narrow to allow the heat from AC units to dissipate. Similarly, some older regional "heritage" trains in the UK and rural parts of Eastern Europe may rely on open windows for ventilation. As of 2026, many rail operators are retrofitting older cars with modern cooling systems to combat increasingly hot summers, but it is always worth checking your specific line if traveling on a historic or local commuter route.