

Suggest use fsfreeze --freeze
to block all access operation to create a stable image without unmount the SD card. (And release it later using fsfreeze --unfreeze
.)
BTW, this feature was created by XFS and was moved to VFS in Linux 2.6.29 so all filesystems supported by Linux gained this feature.
For forecast, you can selfhost a Open-Meteo. But note this need a lot of RAM and storage to run the weather model.
https://github.com/open-meteo/open-meteo