Start by cutting your chilled seedless watermelon into large cubes, ensuring you have about four cups of fruit. Place the cubes in a blender and puree them until smooth, which usually takes about 30 seconds. Strain the mixture through a fine mesh sieve over a bowl to collect the juice, leaving any pulp behind.

In a large pitcher, combine two cups of cold water with half a cup of fresh strained lemon juice. Gradually add about half a cup of granulated sugar, whisking continuously until the sugar fully dissolves.

Gently fold the strained watermelon puree into the pitcher with the lemon-water mixture, stirring until everything is well combined.

Fill your glasses with ice or add ice directly into the pitcher. Pour the refreshing Watermelon Lemonade over the ice and garnish each glass with a sprig of fresh mint.