Make a simple syrup. In a small saucepan, heat the sugar and water to a boil. Stir until the sugar dissolves and allow to cool.

Juice the lemons until you have about a cup and a half.

Puree the watermelon in a blender. Strain through a mesh strainer, or regular colander using cheesecloth. This should yield approximately 5 cups.

In a large pitcher mix together the simple syrup, lemon juice, watermelon juice and cold water. You can adjust to taste by mixing together half of the water, lemon juice, and part of the watermelon juice and simple syrup. Add more of the watermelon and simple syrup to taste. I used 4 ¼ cups total watermelon juice when I made this but it varies a little each time. Add the remainder of the water.

Serve over ice.