Preheat an outdoor grill for high heat, and lightly oil grate.
In a medium bowl, mash together avocados, garlic, yogurt, and lemon juice. Season with salt and pepper.
Rub salmon with dill, lemon pepper, and salt. Place on the prepared grill, and cook 15 minutes, turning once, until easily flaked with a fork. Serve with the avocado mixture.
