First Twin Sensor Alti - Thermo
Air pressure display
As mentioned before, I would always consult this "personal weatherman" before e.g. renting a car to drive to the golf course. Since I was not owning a car, it would have been quite frustrating to have these additional car expenses on top of a rain check.
Almost exactly 6 hours (that is 3 ticks on the air pressure graph) after a sharp decline, it would start to rain. At least that is my experience from Switzerland. There the watch had a special place also, I hung it to the wall as the instrument to check before leaving the house.