Heat vinegar, sugar, and water on the stovetop, whisking to dissolve the sugar. Let cool.
Thinly slice the cucumbers and onion.
Combine the veggies with the dressing in a bowl. Toss with dill, then refrigerate.
Serve this tangy salad as a summer side with: - Burgers - Sandwiches - BBQ - Grilled meals
Chill your cucumber salad for an hour, then dish up!