I think things like heat waves, droughts, blizzards etc. that affect your city and industries in various ways are definitely more interesting (and balanced) than some alien invasion, meteorites or giant killer robots. I always saw highly destructive disasters like this more as a gimmick that you do before reloading your save. Because which city would get constantly struck by highly devastating causes like this? People would simply move to a safer region instead of living in ground 0 of all bad things.