How do I plot my country map with weather data stations?

Question

I've tried this code, but I can't plot the coordinates in my country map.

Weather = {"Ulaanbaatar", "Erdenet"}  

stationtocoordinate = Map[# -> WeatherData[#, "Coordinates"] &, Weather]

---

allWeatherStations = WeatherData[]; fullformStations = FullForm /@ allWeatherStations; Tally[StringLength /@ fullformStations[[All, 1, 2]]] . This code not working. Why?

Answer 1

There is an example of what I think you are trying to do at the end of WeatherData help page, but its a little hard to read. However - here's what I think you want.

(* Function to  Get a list consisting of {CityName, Temp, Co-ords} 
given a Countries weather station, note we get the 1st 
nearest weather station to the city *)

weatherdata[cityname_] := {cityname, WeatherData[#, "Temperature"], 
 WeatherData[#, "Coordinates"]} & /@ WeatherData[{cityname, 1}];

(* Get Names for all Cities *)

cities = CityData[#, "Name"] & /@ CityData[{All, "Mongolia"}];

(*  Get the weather and weather station co-ordinates for the list of 
cities  (the Drop is a kludge to remove the incorrect city "Moron") 
from the weather data *)

wdata = Drop[weatherdata[#] & /@ cities, 9];

(*  Plot the list of city weather stations on a map using GeoPosition to 
correctly plot the co-ordinates*)

GeoGraphics[{Point[GeoPosition[wdata[[All, 1, 3]]]], 
Polygon[Entity["Country", "Mongolia"]], GeoRange -> "Country"}]

I'll leave it as an exercise to change the points to something that changes depending on the temperature. i.e. a disc that changes colour/radius. There are some good examples in the GeoGraphics help.

Answer 2

WeatherData can be told to give you all the weather stations it knows about, but there's more than one type of weather station (and duplicates!):

allWeatherStations = WeatherData[];
fullformStations = FullForm /@ allWeatherStations;
Tally[StringLength /@ fullformStations[[All, 1, 2]]]
(*{{4, 6919}, {5, 10306}, {8, 4697}}*)

Looking at the documentation, I find the "WMO*" stations seem to be the interesting, and reliable ones. I extract these and find their corrdinates:

wmoWeatherStations = Cases[fullformStations[[All, 1, 2]], a_ /; StringLength[a] == 8];
wmoStationsPositions = 
  GeoPosition[WeatherData[#, "Coordinates"]] & /@ wmoWeatherStations;

Using GeoWithinQ I find those stations within Mongolia and then use Pick to include these in GeoGraphics

wmoMongolia = GeoWithinQ[Entity["Country", "Mongolia"], wmoStationsPositions];
GeoGraphics[GeoMarker[Pick[wmoStationsPositions, wmoMongolia]], 
 GeoRange -> Entity["Country", "Mongolia"]]