Start by washing the cucumbers thoroughly under cold water. Pat them dry with a paper towel and then slice them into thin rounds or half-moons, depending on your preference. If you prefer a crunchier salad, leave the skin on; otherwise, peel the cucumbers before slicing.
Next, thinly slice the half of a large red onion.
Take the fresh dill and chop it finely. Dill stems are edible and also have flavor, so feel free to include some of them if you desire.
In a large mixing bowl, combine the cucumbers, red onion, fresh dill, sour cream, red wine vinegar, granulated sugar, garlic powder, salt, and pepper. Mix well until all the ingredients are incorporated.
Cover the bowl with plastic wrap or transfer the salad to an airtight container and refrigerate for at least 30 minutes before serving. Chilling the salad allows the flavors to meld together, resulting in a more delicious and cohesive dish.