Time plays a vital role in Pokémon Sword and Shield. Some Pokémon will only show up when a particular type of weather occurs.
For example, if you visit your PokéDex and look for a Pokémon you want to catch, click on the "Habitat" option by clicking on "X". You will see the entire Galar region and you should see the symbols of the small creatures on the map. These symbols indicate the locations where you can encounter that particular Pokémon. When you hover over one of those locations, you will see that specific weather symbols in the upper left of the screen darken, indicating which climate that Pokémon prefers in that region. A Pokémon's favorite weather changes by area.
Those symbols are useful for seeing visually, but there is no direct name associated with them. We have a breakdown of those symbols and their meanings. There is a method on how players can change the weather in the Wild Area.
Neve / Hail