Porygon

I hatched mine. Also, have never seen one in wild and am in Central NY.

I'm in the UK, and whilst not common find them around town - basically the same places you'd expect to find Jigglypuffs - just ordinary town streets. Probably caught a dozen over 33 levels...

I've never seen wild Snorlax, Aerodactyl, Chansey or Lapras and don't know any local trainers who have. Some of the rarer pokes seem to be very thinly distributed.

I caught one in Carol gardens Brooklyn NY When I was on vacation. he was near the park. Also hatched one I would hope for a egg.

Porygon is a legend for me as well. Hatched 3 of them luckily, but have never seen it in the wild.

I'm in So. cal as well. I found a Porygon in Newport Beach of all places during one of my never-ending hunts for a Lapras. Then I hatched one a few days later so it might have been from an egg I picked up there.

Still looking for that Lapras...

Ever since the beginning of the game a porygon spawns at the end of my street every once in a while. It seems really randomly when this happens. I even got to the point that I don´t catch them anymore when I see them on my radar.

My street is just an average street. Nothing special about it. I hope you will find your porygon some day.

Only time I have ever seen a porygon on sightings is on the 3rd street promenade, right near santa monica pier if you are not familiar. I have also hatched 5 of them, all from eggs from santa monica pier if that even matters. I have also heard of people getting them from disneyland.

Porygon never spawned in my area. I got very lucky and hatched two, but the better one have 80% IVs.

I've caught only on in the wild but I was on business in NY. Caught it in Manhatten near Wall Street, of all places. I've been lucky to hatch 6 out of eggs. Your best chance is likely to hatch one.

There are a couple spots near me that spawn them.

He's a rare spawn so instead of having nests there's normally a spawn point where they have an X% chance to show up each time it spawns a Mon - but only at one spot. Could be down the street, could be 20 miles away. Keep an eye on the rare spawn points in your area and try to figure out what they're spitting out.

There's a couple rare spawn points within a few blocks of where I live and they seem to be about 25% chance to show up each time Pokemon spawns. The one right next to my apt building has gone from Machop to Onix to Omanyte; it changes every so often (not always every migration)

What I'd do is check the silphroad nest atlas and look for past sightings. Make sure the date is recent - if it was a month or 2 ago it's probably moved.

https://thesilphroad.com/atlas

In my experiences, I see porygon once every 3 or so weeks. I see it show up on spawn points that have lots of pidgeys/Ratattas/normal types spawning.

I find them all in residential areas.