It's also based on nearby activity as well, apparently. Many complaints from people in rural areas and people who hike and such saying they can't find anything because of the low activity in the area.
In general, the data used for determining the # of pokemon in areas is all pulled from Ingress.
Ingress is heavily based on cell usage so areas that have high cell usage will have more pokemon, meaning rural areas have a low quantity and often can only catch the same 5-10 pokemon and at a slower rate.
Because of this gas stations are a very good place for catching pokemon.
In general, the data used for determining the # of pokemon in areas is all pulled from Ingress.
Ingress is heavily based on cell usage so areas that have high cell usage will have more pokemon, meaning rural areas have a low quantity and often can only catch the same 5-10 pokemon and at a slower rate.
Because of this gas stations are a very good place for catching pokemon.
that's weird. I work at the airport and no pokemon spawn there unless lures or incenses are used. and everyone has a cell phone at the airport lol