Return Observable in callback rxjava

I am messing around some with the google awareness api and now my understanding of RxJava is limiting me.

What I want to achieve in the end: I want to get a Weather and a Location from the Api, and merge them into one object that I can pass on to my view for update.

However, I'm not sure how I achieve the retuing of an Observable from the api callback here, and how to achieve merging of the weather and location object from api.getWeather and api.getLocation

public void requestUserCurrentInfo() {
    Subscription userInfo = getWeatherLocation().subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread()).subscribe(userinfo ->
                    Log.d(TAG,userinfo.something()));
}

public Observable<UserInfo> getWeatherLocation () {
    try {
        Awareness.SnapshotApi.getWeather(client)
                .setResultCallback(weather -> {
                    if (!weather.getStatus().isSuccess()) {
                        Log.d(TAG, "Could not get weather");
                        retu;
                    }
                    //How do I do here?
                    retu weather.getWeather();
                });


        Awareness.SnapshotApi.getLocation(mGoogleApiClient)
            .setResultCallback(retrievedLocation -> {
                if(!retrievedLocation.getStatus().isSuccess()) retu;
                Log.d("FRAG", retrievedLocation.getLocation().getLatitude() + "");
            });


    } catch (SecurityException exception) {
        throw new SecurityException("No permission " + exception);

    }

}