I think you will find this link helpful: http://www.pokemongodb.net/2016/04/pokemon-go-types.html
It has a chart at the top showing what percentage of Kanto pokemon belong in each type. Below, it shows a list of all Pokemon in the game and after that there is a chart showing what type of Pokemon to expect in various Biomes.
Happy Hunting!
Possible Types
Normal
Boundaries, Landuse, Places, Roads, Transit, College, Commercial,
Common, Footway, Hospital, Hotel, Library, Major Road, Minor Road,
Pedestrian, Pitch, Playa, Recreation Area, Retail, Runway, School,
Sports Center, Stadium, University
Grass
Landmass, Farm, Farmland, Farmyard, Forest, Garden, Golf Course,
Grass, Meadow, Nature Reserve, Park, Path, Playground, Residential,
Wood
Bug
Farm, Farmland, Farmyard, Forest, Garden, Golf Course, Grass, Nature
Reserve, Park, Path, Playground, Wood
Water
Water, Basin, Canal, Dock, Drain, Glacier, Lake, Ocean, Reservoir,
River, Riverbank, Stream
Flying
Farm, Farmland, Farmyard, Forest, Garden, Grass, Nature Reserve, Park,
Wood
Rock
Building, Landmass, Highway, Industrial, Parking, Quarry, Railway,
Urban Area
Ground
Landmass, Ditch, Land, Parking, Playground, Railway, Taxiway, Urban
Area
Fairy
POIs, Cemetery, Place of Worship
Dark
Cemetery, Cinema, Theatre
Steel
Building, Railway
Dragon
POIs
Ghost
Cemetery
Ice
Glacier
Psychic
Hospital?
Electric
Industrial
Fire
Residential?
Poison
Wetland
Pokemon spawns are very much affected by location.
The real world is split up into a number of biomes. Spawn chances, rates, and available Pokemon are very much biome dependent. This data is likely pulled from Google Maps and Ingress, with some minor alterations.
For example, it is far more likely for a Muk to spawn in an Urban environment than it is for it to spawn in a Meadow.
Biome List
- BASIN
- CANAL
- CEMETERY
- CINEMA
- COLLEGE
- COMMERCIAL
- COMMON
- DITCH
- DOCK
- DRAIN
- FARM
- FARMLAND
- FARMYARD
- FOOTWAY
- FOREST
- GARDEN
- GLACIER
- GOLF_COURSE
- GRASS
- HIGHWAY
- HOSPITAL
- HOTEL
- INDUSTRIAL
- LAKE
- LAND
- LIBRARY
- MAJOR_ROAD
- MEADOW
- MINOR_ROAD
- NATURE_RESERVE
- OCEAN
- PARK
- PARKING
- PATH
- PEDESTRIAN
- PITCH
- PLACE_OF_WORSHIP
- PLAYA
- PLAYGROUND
- QUARRY
- RAILWAY
- RECREATION_AREA
- RESERVOIR
- RESIDENTIAL
- RETAIL
- RIVER
- RIVERBANK
- RUNWAY
- SCHOOL
- SPORTS_CENTER
- STADIUM
- STREAM
- TAXIWAY
- THEATRE
- UNIVERSITY
- URBAN_AREA
- WETLAND
- WOOD
- DEBUG_TILE_OUTLINE
- DEBUG_TILE_SURFACE
- OTHER
Best Answer
No, it's not. For starters, here's a Gastly around 4pm in the afternoon.
I've also been playing the game until 2 am every night since the game was released and haven't seen a single ghost-type Pokémon in the wild at night. It is doubtful that time of day is a factor for them, which means they're probably location dependent, just like other Pokémon.