Preheat oven to 300°F. Wrap hot dog buns in foil.
Brown the ground beef with half of the chopped onions in a large skillet over medium-high heat, breaking it up as it cooks until no longer pink and the onion has softened, about 5 minutes.
Add in the chili powder, cumin, salt, pepper, garlic powder, and celery salt. Cook for another 3 minutes, stirring occasionally.
Add tomato sauce, water, mustard, and Worcestershire sauce. Once the mixture comes to a boil, reduce the heat to low and simmer for 20 minutes until thickened. Add additional water, if needed, if the mixture becomes too thick.
While the sauce simmers, wrap the hot dog buns in foil and place them in the oven to heat through for about 10 minutes.
Bring a large pot of water to a boil. Add the hot dogs and cook for 5-7 minutes until heated through.
To assemble, place a hot dog in each on the warmed buns and top with the chili. Sprinkle shredded cheese and finely diced onion on top, then finish with a squirt of yellow mustard. Serve immediately.
