Preheat the oven to 200 degrees Celsius. Using a large mixing bowl, add in the cumin, paprika, onion powder, chili powder, salt, and pepper to taste then mix properly to combine, set aside. In another mixing bowl, add in the oil and lemon juice then mix to combine. Coat the salmon with the juice mixture then place in a baking dish.
Place the baking dish into the preheated oven and bake the salmon for about twelve to fifteen minutes until it is cooked through. In the meantime, using a mixing bowl, add in the diced avocado, diced cucumber, onions, bell pepper, lemon juice, oil, cumin, salt, and pepper to taste then toss to combine. This makes the salsa.
Serve the salmon with the salsa then garnish with chopped cilantro, enjoy.