In a small bowl, combine the room temperature butter, salt, black pepper, garlic powder, lemon juice, and lemon zest. Stir until well combined and the mixture is uniform. Fold in the fresh dill gently to distribute it evenly throughout the butter. Set aside at room temperature so it stays spreadable.

Preheat your grill to medium-high heat (around 375-400°F). While the grill heats, tear off 6 pieces of heavy-duty aluminum foil, each about 12 inches long. Place one ear of corn in the center of each foil piece, then divide the herb butter from Step 1 evenly among the 6 ears, spreading it generously over the top and sides of each corn cob. Wrap each ear tightly in foil, making sure the seams are sealed to trap the steam and butter inside.

Place the foil-wrapped corn directly on the grill grates with the lid closed. I like to rotate each ear a quarter turn every 2-3 minutes to ensure even cooking and prevent any side from charring too much. This rotation keeps the butter heating evenly around the corn. Grill for 15-20 minutes total until the corn is tender when pierced with a fork (you can carefully unwrap a small corner of foil to test).

Carefully remove the corn from the grill using tongs, as the foil will be very hot and the steam inside will be intense. Let the corn rest in the foil for 1-2 minutes to allow the butter to fully absorb into the kernels. Unwrap the foil away from your face to avoid the hot steam, then serve immediately while warm.