GPX Viewer supports showing OpenWeatherMap weather overlays over online maps. OpenWeatherMap works only with online maps and it also needs a device to be connected to the internet.

Below are step-by-step instructions on how to show OpenWeatherMap.

1. First off you need to start GPX Viewer.
2. On the map screen tap on … button in top right corner in top toolbar and from menu select OpenWeatherMap. If you have hidden this button, open the left main menu, then tap on the Settings button. In the settings screen tap on the Maps button and then OpenWeatherMap.
3. In the shown dialog choose some overlay that you want to be shown over the online map in GPX Viewer.

Below is a video showing the instructions above: