Trouble connecting weather app and retrieving JSON data?

public class MainActivity extends ActionBarActivity {

    public static final String TAG = MainActivity.class.getSimpleName();

    private CurrentWeather mCurrentWeather;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        String apiKey = "0480430260d54cff60991a1ab0cf22c2";
        double latitude = 37.8267;
        double longitude = -122.423;
        String forecastUrl = "https://api.forecase.io/forcast/" + 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(Request request, IOException e) {

            }

            @Override
            public void onResponse(Response response) throws IOException {
                try {
                    String jsonData = response.body().string();
                    Log.v(TAG, jsonData);
                    if (response.isSuccessful()) {
                        mCurrentWeather = getCurrentDetails(jsonData);
                    }
                    else {
                        alertUserAboutError();
                    }
                }
                catch (IOException e) {
                    Log.e(TAG, "Exception caught: ", e);
                }
                catch (JSONException e) {
                    Log.e(TAG, "Exception caught: ", e);
                }
            }
        });}
        else {
            Toast.makeText(this, getString(R.string.network_unavalable_message), Toast.LENGTH_LONG).show();
        }

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

    }

    private CurrentWeather getCurrentDetails(String jsonData) throws JSONException {
        JSONObject forecast = new JSONObject(jsonData);
        String timezone = forecast.getString("timezone");
        Log.i(TAG, "From JSON: " + timezone);

        return new CurrentWeather();
    }

    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");
    }


}

public class AlertDialogFragment extends DialogFragment {
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        Context context = getActivity();
        AlertDialog.Builder builder = new AlertDialog.Builder(context)
                .setTitle(context.getString(R.string.error_title))
                .setMessage(context.getString(R.string.error_message))
                .setPositiveButton(context.getString(R.string.error_ok_button_text), null);

        AlertDialog dialog = builder.create();
        return dialog;
    }
}

public class CurrentWeather {
    private String mIcon;
    private long mTime;
    private double mTemperature;
    private double mHumidity;
    private double mPrecipChance;
    private String mSummary;

    public String getIcon() {
        return mIcon;
    }

    public void setIcon(String icon) {
        mIcon = icon;
    }

    public long getTime() {
        return mTime;
    }

    public void setTime(long time) {
        mTime = time;
    }

    public double getTemperature() {
        return mTemperature;
    }

    public void setTemperature(double temperature) {
        mTemperature = temperature;
    }

    public double getHumidity() {
        return mHumidity;
    }

    public void setHumidity(double humidity) {
        mHumidity = humidity;
    }

    public double getPrecipChance() {
        return mPrecipChance;
    }

    public void setPrecipChance(double precipChance) {
        mPrecipChance = precipChance;
    }

    public String getSummary() {
        return mSummary;
    }

    public void setSummary(String summary) {
        mSummary = summary;
    }
}