Some cities have various regular developer meetings, often devoted to programming languages (e.g. Perl, Python, Java) or areas (web development, embedded devices, even scripting languages).

It might be worth going on a city group on Reddit and asking about any, and otherwise try to start one.

One thing to keep in mind is that different times of day are good for different people.

Evening meetings every month in pubs are popular, but for many reasons a lot of people don't like to go to pubs or drink alcohol with strangers.

Meetings during lunch or morning "techie brekkie" before work are sometimes popular, but ideally in a central location where it's easy for developers can easily get to before work or during lunch.