Getting null response from retrofit

Question

Trying to make a weather app with retrofit and I'm struggling to understand what's going on here and if anyone could help me?

Here is the class for getting weather:

public class WeatherOWM {


private double latitude;
private double longitude;
private Context ma;
private MainActivity x;
private ForecastAdapter weatherData;
public static String baseUrl = "http://api.openweathermap.org/";
public static String appId = "insertapikey";
private Context context;
private RecyclerView recyclerView;
private RecyclerView.LayoutManager layoutManager;


public WeatherOWM(double latitude, double longitude, Context ma, MainActivity x){
    this.latitude = latitude;
    this.longitude = longitude;
    this.ma = ma;
    this.x = x ;
}


public void getWeatherOWM() {
    HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
    OkHttpClient.Builder httpClient = new OkHttpClient.Builder();
    logging.setLevel(HttpLoggingInterceptor.Level.BODY);
    httpClient.addInterceptor(logging);

    String lat = String.valueOf(latitude);
    String lon = String.valueOf(longitude);

    //Create Retrofit Instance
    Retrofit retrofit = new Retrofit.Builder()
            .baseUrl(baseUrl)
            .addConverterFactory(GsonConverterFactory.create())
            .client(httpClient.build())
            .build();

    //Get client & call object for the request
    WeatherServiceOWM serviceOWM = retrofit.create(WeatherServiceOWM.class);
    Call<WeatherResponse> call = serviceOWM.getWeatherForecast(lat, lon, appId);

    //Execute network request
    call.enqueue (new Callback <WeatherResponse>() {
        @Override
        public void onResponse(Call <WeatherResponse> call, Response<WeatherResponse> response) {
            if(response.body() != null) {
               WeatherResponse weatherResponse;
               weatherResponse = response.body();
               System.out.println("CODE: 200");
               System.out.println(weatherResponse.get);
            }
        }

        @Override
        public void onFailure(Call<WeatherResponse> call, Throwable t) {
            System.out.println("CONNECTION ERROR");
        }
    });
 }
}

My Retrofit openweathermap class:

    private double latitude;
private double longitude;
private Context ma;
private MainActivity x;
private ForecastAdapter weatherData;
public static String baseUrl = "http://api.openweathermap.org/";
public static String appId = "insertapikey";
private Context context;
private RecyclerView recyclerView;
private RecyclerView.LayoutManager layoutManager;


public WeatherOWM(double latitude, double longitude, Context ma, MainActivity x){
    this.latitude = latitude;
    this.longitude = longitude;
    this.ma = ma;
    this.x = x ;
}


public void getWeatherOWM() {
    HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
    OkHttpClient.Builder httpClient = new OkHttpClient.Builder();
    logging.setLevel(HttpLoggingInterceptor.Level.BODY);
    httpClient.addInterceptor(logging);

    String lat = String.valueOf(latitude);
    String lon = String.valueOf(longitude);

    //Create Retrofit Instance
    Retrofit retrofit = new Retrofit.Builder()
            .baseUrl(baseUrl)
            .addConverterFactory(GsonConverterFactory.create())
            .client(httpClient.build())
            .build();

    //Get client & call object for the request
    WeatherServiceOWM serviceOWM = retrofit.create(WeatherServiceOWM.class);
    Call<WeatherResponse> call = serviceOWM.getWeatherForecast(lat, lon, appId);

    //Execute network request
    call.enqueue (new Callback <WeatherResponse>() {
        @Override
        public void onResponse(Call <WeatherResponse> call, Response<WeatherResponse> response) {
            if(response.body() != null) {
                WeatherResponse weatherResponse = response.body();
                System.out.println("CODE: 200");
                System.out.println(weatherResponse.weather_OWM.get(0).description);
            }
        }

        @Override
        public void onFailure(Call<WeatherResponse> call, Throwable t) {
            System.out.println("CONNECTION ERROR");
        }
    });
}
}

My response class(s):

public class WeatherResponse {


@SerializedName("coord")
@Expose
public Coord coord;
@SerializedName("weather")
@Expose
public List<Weather> weather_OWM;
@SerializedName("main")
@Expose
public Main main;
@SerializedName("wind")
@Expose
public Clouds clouds;
@SerializedName("dt")
@Expose
public Double dt;
@SerializedName("id")
@Expose
public Double id;
@SerializedName("name")
@Expose
public String name;
@SerializedName("cod")
@Expose
public Double cod;

public class Clouds {

    @SerializedName("all")
    @Expose
    public Double all;

}
public class Coord {

    @SerializedName("lon")
    @Expose
    public Double lon;
    @SerializedName("lat")
    @Expose
    public Double lat;

}
public class Main {

    @SerializedName("temp")
    @Expose
    public Double temp;
    @SerializedName("humidity")
    @Expose
    public Double humidity;
    @SerializedName("pressure")
    @Expose
    public Double pressure;
    @SerializedName("temp_min")
    @Expose
    public Double tempMin;
    @SerializedName("temp_max")
    @Expose
    public Double tempMax;

}
public class Weather {

    @SerializedName("id")
    @Expose
    public Double id;
    @SerializedName("main")
    @Expose
    public String main;
    @SerializedName("description")
    @Expose
    public String description;
    @SerializedName("icon")
    @Expose
    public String icon;

}

public Coord getCoord() {
    return coord;
}

public void setCoord(Coord coord) {
    this.coord = coord;
}

public List<Weather> getWeather() {
    return weather_OWM;
}

public void setWeather(List<Weather> weather) {
    this.weather_OWM = weather;
}

public Main getMain() {
    return main;
}

public void setMain(Main main) {
    this.main = main;
}

public Clouds getClouds() {
    return clouds;
}

public void setClouds(Clouds clouds) {
    this.clouds = clouds;
}

public Double getDt() {
    return dt;
}

public void setDt(Double dt) {
    this.dt = dt;
}

public Double getId() {
    return id;
}

public void setId(Double id) {
    this.id = id;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public Double getCod() {
    return cod;
}

public void setCod(Double cod) {
    this.cod = cod;
}
}

And my interface:

public interface WeatherServiceOWM {
@GET("data/2.5/forecast?")
Call <WeatherResponse> getWeatherForecast(@Query("lat") String lat, @Query("lon") String lon, @Query("appid") String app_id);

}

Now the issue is that I'm getting a NPE. The data is coming through fine as I can see the response in the logs but I get the NPE when trying to print it out with this:

System.out.println(weatherResponse.weather_OWM.get(0).description);