Blend watermelon, strawberries, lime juice, apple cider, and water until smooth. Taste to see of the sweetness is to your liking. Feel free to add more watermelon or apple cider if you want a sweeter beverage.

You can serve the drink immediately or refrigerate it for an hour to let the flavors set. If you are refrigerating it, I like to add some cucumber slices and a few sprigs of mint to the agua fresca to give it more flavor.

Serve agua frescas with ice and garnish with lime slices, cucumber slices, and mint leaves.

Refrigerate leftovers for up to 3 days.