How do you say hello in Helsinki?

The most common way to say hello in Helsinki, Finland is "Hei".

It's a casual greeting used in most situations, both formal and informal.

You can also use "Moikka" which is a more informal and friendly greeting.

For more formal situations, you might use "Hyvää päivää" (Good day) or "Hyvää iltapäivää" (Good afternoon).