According to the explanations in the Apple support document, iOS 16.4.1 removes two vulnerabilities that allow arbitrary code execution with kernel privileges. The company has also fixed the issues listed below in the operating system:
- Different skin colors not showing in right or left swiping hand emoji
- Siri not responding in some cases
No change to Weather app
Despite the recent problems with the Weather application, it seems that no change has been made in this regard in iOS 16.4.1. Probably a server-side issue. You can install the new update on your iPhone by going to Settings > General > Software Update.