Help! Error - Not getting weather data

public static final String TAG = MainActivity.class.getSimpleName();
@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    String apiKey = "7bd5e39b849d70b6211ebcaf98b00dd4";
    double longitude =37.8267;
    double latitude = -122.423;
    String forecastUrl = "https://api.forecast.io/forecast/" + apiKey + "/" + latitude + "," + longitude;

    if (isNetworkAvailable())
    {


        OkHttpClient client = new OkHttpClient();

        Request request = new Request.Builder().url(forecastUrl).build();

        Call call = client.newCall(request);
        call.enqueue(new Callback()
        {
            @Override
            public void onFailure(Call call, IOException e)
            {
                Log.d(TAG, "Error in the data code");
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException
            {
                try
                {
                    //Response response = call.execute(); execute() is the synchronous method
                    Log.v(TAG, response.body().string());
                    if (response.isSuccessful())
                    {
                        //Log.v(TAG, response.body().string()); //string representation of the response body
                    } else
                    {
                        //Log.v(TAG,response.body().string());
                        alertUserAboutError();
                    }
                } catch (IOException e)
                {
                    Log.e(TAG, "Exception caught: ", e);
                }

                response.close();
            }


        });
    }
    else
    {
        Toast.makeText(this, R.string.network_unavailable_message, Toast.LENGTH_LONG).show();
    }

    Log.d(TAG, "Main UI code is running");


}

private boolean isNetworkAvailable()
{
    ConnectivityManager manager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo networkInfo = manager.getActiveNetworkInfo();
    boolean isAvailable = false;

    if (networkInfo != null && networkInfo.isConnected())
    {

        isAvailable=true;

    }
    return isAvailable;
}

private void alertUserAboutError()
{
    AlertDialogFragment dialog = new AlertDialogFragment();
    dialog.show(getFragmentManager(), "error_dialog");
}