There are multiple historic weather APIs available (example), it should be pretty trivial to write a script to read the location and time from the EXIF data of your images, call the API, and them dump the info into a list or back into the image metadata.
It wouldn’t be difficult to write this script as a darktable plugin, but I imagine you’d struggle to convince the maintainers to merge code to allow for searching or categorising based on a custom metadata tag.
I’m less familiar with other programs, but I don’t see any of the proprietary options implementing this.