Cut the cucumbers in half lengthwise. With a spoon, scoop out the seeds and discard them. Slice the cucumber halves crosswise in 1/8-inch pieces. Place in a colander set over a bowl. Toss with salt. Let stand 15 minutes.
In a medium bowl, combine the yogurt, dill, vinegar, and pepper. Remove the cucumbers from the colander and pat with paper towels. Add to bowl with the yogurt dressing and toss to combine. Garnish with the dill sprigs.