Unfortunately right now there is no reliable way to receive a broadcast event after your applicaiton has been installed, the ACTION_PACKAGE_ADDED Intent does not broadcast to the newly installed package.
You will have to have a broadcast receiver class as well as your service in order to receive the ACTION_BOOT_COMPLETED event. I would also recommend adding the ACTION_USER_PRESENT intent to be caught by that broadcast receiver, this requires Android 1.5 (minSDK=3), this will call your broadcast receiver whenever the user unlocks their phone. The last thing that you can do to try to keep your service running without having it easily be shut down automatically is to call Service.setForeground() in your service onCreate to tell Android that your service shouldn't be stopped, this was added mainly for mp3 player type services that have to keep running but can be used by any service.
Make sure you add the proper permissions for the boot_complete and user_present events in you manifest.
Here is a simple class that you can use as a broadcast receiver for the events.
public class WeatherStatusServiceReceiver extends BroadcastReceiver
public void onReceive(Context context, Intent intent)
if(intent.getAction() != null)
context.startService(new Intent(context, WeatherStatusService.class));