It won't take long to encounter Pokémon Pokémon Go as you roam the world. However, your position in the real world matters. For example, the closer you get to water, the more likely you are to find a Water-type Pokémon.
For many, Dragon-type Pokémon can be particularly frustrating to catch. These are some of the rarer encounters to be found in the game, although some players are lucky, like finding them on a windy day while near the water. It varies according to your luck.
Some players have reported finding Dragon-type Pokémon in parks, large city districts, and exploring on windy days.
Unfortunately, you won't have any bait available to take them to a reliable PokéStop. Alternatively, you can choose to activate an incense on your character, attracting a variety of Pokémon to your location. The problem with this strategy is that more Pokémon will arrive at your location, many of which are likely not Dragon-type. There are some that are easier than others, such as Kingdra, Bagon or Gible.
Some random research tasks reward Pokémon random encounters. You can get them from spinning PokéStops, which can increase your chances of landing a Dragon type without finding one in the wild, but that's a bit of luck too.
There is no surefire way to get Dragon-type Pokémon. It's a lot of trial and error to explore your area, waiting to find more Pokémon. However, you may want to be on the lookout for a windy day, as many players believe those when they have found one.