From my previous answer:
Reddit's r/TheSilphRoad subreddit has updated a regional map for Generation 2.
This image shown here is constructed from this link, supplemented with images from Bulbapedia. The link includes some details about these boundaries, which I will add below.
Covers all major Canadian cities, no further North than Calgary, somewhere between 51˚ and 52°N, but the North East section might be a little more unclear. South as far as 29˚N. Heracross starts where it stops
Reported as far North as 61˚, does not cover all of Norway. Not found in Gibraltar but in Northern Tunisia. Found in Sicily but not Malta. As far West as the Azores. South Eastern border a little more unclear but as far East into Russia as Kazan
All of Japan, South Korea, and reports of Vladivostok and Eastern Russia as well as areas of Northern China. Covers all of Taiwan. Covers all of Hong Kong and any areas of China South of there.
Covers Australia, including Tasmania, as well as Papua New Guinea.
No higher than 31˚N and not found more than 300km inland, southern limit still disputed. 26˚S in Australia, Chile, Madagascar and Mauritius, but lower in Brazil. Confirmed in Nairobi most likely due to Lake Victoria being such a large body of water.
Starts at 29˚N and covers the Caribbean, Central and South Americas. Most likely reaches all the way to the Southern tips of Argentina and Chile.
Note that an alternate map slightly adjusts the borders, with it being notable that Corsola do not exist very far inland. The Tauros border also extends farther north into Canada, although not completely covering it. Farfetch'd also covers more parts of China.
Credit to u/oktimeforplanb post on r/silphroad (With their image at that link).