Many other stackexchange sites have singed up for the winter hat bash. It's a bit silly, but adds a degree of fun which in return may add some activity. I'm not sure if it's already too late to activate it in here this year, was this considered ?
We have activated it here. You should see the hats by default (on the main site, but not here on meta). If you don't, you may need to turn them on, click the snowflake on the top bar