Cucumber and Sweet-Onion Salad

3 English cucumbers, halved lengthwise and thinly sliced on the diagonal
1 medium sweet onion, such as Vidalia, halved and thinly sliced
1/2 cup fresh dill, coarsely chopped
3 tablespoons olive oil
3 tablespoons fresh lemon juice
2 tablespoons white-wine vinegar
Coarse salt and ground pepper

Directions
In a large bowl, toss together cucumbers, onion, dill, oil, lemon juice, and vinegar; season with salt and pepper.