Cut your watermelon into 1-inch cubes and remove all seeds—this is important for texture, as seeds can make the popsicles gritty. Add the cubed watermelon to a blender along with the lime juice, honey, and sea salt. Blend on high speed until completely smooth, about 1-2 minutes. The salt might seem like an odd addition, but I find it actually enhances the watermelon flavor and prevents the popsicles from tasting overly sweet.

Pour the blended watermelon mixture into popsicle molds, filling each one to about 1/2 inch below the rim—this space allows room for the mixture to expand slightly as it freezes. Insert the popsicle sticks into each mold, then place the entire mold in the freezer. Freeze for at least 4 hours, though overnight freezing ensures the popsicles are completely solid and easier to remove from the molds.