Why Are Buses and Subways in the U.S. So Cold?

If you’ve ever stepped onto a bus or subway in the U.S., you’ve probably felt it right away — that icy blast of air that makes you wonder if you’ve just walked into a freezer. For many newcomers, it’s one of the most surprising everyday experiences in America. But why are public transportation systems here so cold?

Cool air means comfort

In the U.S., cool air isn’t just about temperature — it’s about comfort, freshness, and even professionalism. Being in a well-air-conditioned space often signals modernity and good maintenance. So, whether it’s an office, store, or bus, Americans tend to associate “cool” air with a pleasant environment.

Overpowered central systems

Most public buses and trains use central air systems that have only one setting — cold. They’re designed to cool down large spaces quickly, with no real sensitivity to outside temperature or the number of passengers on board. The result? Even when it’s mild outside, the AC keeps blowing at full strength.

A tool for hygiene and odor control

Strong air conditioning isn’t just for comfort; it also helps reduce humidity and prevent unpleasant odors in crowded areas. In big cities especially, the AC doubles as a way to keep public spaces drier and fresher during rush hours.

Americans dress for it

Locals know the drill — even in summer, you’ll see people carrying a light sweater or hoodie. It’s almost a cultural habit: you never know when the AC will be blasting indoors, so it’s best to be prepared. For visitors, though, that chill can come as a shock.

Energy culture and the “more is better” mindset

Historically, electricity has been relatively affordable in much of the U.S., especially in southern states. That, combined with a “comfort first” culture, has made blasting the AC almost second nature — even if it’s not always eco-friendly.

If you’re visiting or new to the U.S., don’t be surprised if you need a sweater in the middle of summer — especially on public transportation.

And if you’re in Texas, it’s even more extreme: step outside and it’s desert heat, step inside and it’s the Arctic.

Welcome to the land of big skies, big flavors — and even bigger air-conditioning.