@magicalmilly it depends on where you live
and honestly on the current local weather agencies
living in indianapolis area for 23 years, it was variously either background noise or actually something to be scared of, because they kept changing the rules and it either happened weekly or literally only happened if you were about to be struck by a tornado
@magicalmilly in recent years? basically never
when i was in like, middle school, if you heard a tornado siren, that meant "hide, right the fuck now"
then they changed things, and by the end of high school you'd have tornado sirens going off during, no joke, a light sprinkle with the sun shining and nothing on the radar
the mastodon instance at cybre.space is retired
see the end-of-life plan for details: https://cybre.space/~chr/cybre-space-eol