The dynamics of the game will change greatly once more is added, such as tents and vehicles and more of the group-based aspects. Right now it is very much-so a KOS fest because there really isn't much to do except right around and get in to fire-fights.
A thermometer would be helpful if you find one that isn't damaged, but a weather station doesn't quite seem viable as players wouldn't know how to operate the equipment or read the data (for distant forecasting), as well as needing to power the station.
A weather station, however, would work (if able to get up and running) to just see any storms/precipitation in the immediate area (within a number of km) of the station on a display of green/yellow/red/magenta, which could maybe forecast for the next 30-60 minutes (not days).