Every school and school district in suburban Philadelphia, and every private school within the city (and perhaps the city's public and archdiocesan schools individually, but I'm not sure), has a "snow closing number", or just "snow number". Every kid at every school commits their number to memory sometime between September and December of their first year at a school, and it quickly becomes their favorite number. Mine was 120 for my first 6 years of school, and 367 for most of the time after that.
On any morning when there's inclement weather, the popular news radio station here, instead of doing all the news in half-hour cycles, will instead spend only about 5 or 7 minutes on the news. The remainder of the half hour is spent reading out sequential-by-county snow numbers of every school that's closed, has a late opening, has bus service or morning kindergarten canceled, or whatever else was affected by weather. Every kid I knew would listen to the radio as soon as they woke up in the morning, and if they heard their number, would develop a huge grin and then go right back to sleep. Don't cough when numbers near yours are being read, though; you might miss it. And then have to wait another half hour (or hour for particularly bad storms) to hear the number come around again.
My schools were always small enough that there were phone chains to alert everyone to closings, making the numbers strictly unnecessary. And almost all of my schools automatically closed whenever Philadelphia school district closed (which would be announced in full sentences rather than numerically). So the snow number thing was rarely the first way I found out. But still, if you ever go up to me, and say as quickly as possible, "three sixty-one, three sixty-two, three sixty-three, three sixty-four, three sixty-five, three sixty-six...", I guarantee I will involuntarily hold my breath and my heart rate will go up a bit.
A quick google seems to indicate that Philly is the only city that does this. And with the advent of the internet, it's probably on its way out. So sad.