okhttp responsebody can not be converted to a string. Please help...

package com.course.practising.stormy;

import android.app.Activity;
import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;

import com.squareup.okhttp.Call;
import com.squareup.okhttp.Callback;
import com.squareup.okhttp.OkHttpClient;
import com.squareup.okhttp.Request;
import com.squareup.okhttp.Response;

import org.json.JSONException;
import org.json.JSONObject;

import java.io.IOException;


public class MainActivity extends Activity {

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

    private CurrentWeather mCurrentWeather;

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

        //double latitude = 37.8267;
        //double longitude =  -122.423;
        String apiKEY = "385402ba95335407fae83737763a0984";
        //String forecastUrl = "https://api.forecast.io/forecast/" + apiKEY + "/" + latitude + "," + longitude;

        String forecastUrl = "https://api.forecast.io/forecast/385402ba95335407fae83737763a0984/-6.8,39.2833";

        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 {
                        Log.v(TAG, "Check Log " + response.body().string());
                        String jsonData = response.body().string();
                        Log.v(TAG, jsonData.toString());
                        if (response.isSuccessful()) {
                                mCurrentWeather = getCurrentDetails(jsonData);
                        } else {
                            alertUserAboutError();
                        }
                    } catch (IOException e) {
                        Log.v(TAG, "Exception caught : ", e);
                    }catch (JSONException e)
                    {
                        Log.v(TAG, "Exception caught : ", e);
                    }
                }
            });

            Log.d(TAG, "Main thread is running");
        }
        else {
            Toast.makeText(this,getString(R.string.network_unavailable_message),Toast.LENGTH_SHORT).show();
        }

    }

    private CurrentWeather getCurrentDetails(String jsonData) throws JSONException {

        JSONObject forecast = new JSONObject(jsonData);
        String timezone = forecast.getString("timezone");
        Log.v(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 alert = new AlertDialogFragment();
        alert.show(getFragmentManager(), "error_dialog");
    }
}