Wash the cucumbers, peel them if needed, and slice them thinly.

Place the cucumber slices in a large bowl and sprinkle them with salt.

Let the cucumbers sit for 30 minutes to release water.

While the cucumbers rest, mix the vinegar, sugar, black pepper, garlic powder, and optional celery seed in a small bowl.

Drain the liquid from the cucumbers and pat or wring them dry with a towel.

Add the red onion and dill to the cucumbers.

Pour the dressing over the salad and toss to combine.

Refrigerate for at least 1 hour before serving, stirring once or twice.