In a medium bowl, combine the diced avocado, chopped tomato, diced red onion, corn, minced jalapeño, and fresh cilantro. Pour in the lime juice and sprinkle with salt, then gently fold everything together with a rubber spatula—be careful not to break down the avocado pieces. Set aside at room temperature.

Pat the salmon fillets dry with paper towels. In a small bowl, whisk together the salt, chili powder, smoked paprika, onion powder, garlic powder, black pepper, and ground cumin. Brush both sides of each salmon fillet lightly with olive oil, then generously coat all sides with the spice mixture, pressing gently so it adheres. Let the seasoned salmon sit at room temperature for 2-3 minutes while you preheat the grill.

Heat your grill to medium heat (about 400°F) and lightly oil the grates. Place the salmon fillets skin-side up on the grill and cook for 4-5 minutes without moving them. Flip the fillets carefully and grill for another 3-4 minutes until cooked through. Let the salmon rest for 2 minutes after grilling.

Transfer the grilled salmon fillets to serving plates, skin-side down. Top each fillet generously with the avocado salsa from Step 1 and serve immediately.