How much time have you spent looking threads on this forum. People have described their Arduino project, sometime in detail.
MY personal applications are 1, an anemometer that runs 24/7. My irrigation system storage tank control is by Arduino and has run for 4 years. I did several for my previous electronic assembly business, a coils winder, a drying oven, a solder paste refrigerated storage chamber using a Peltier device.
Many people have extensive remote weather stations.