Prep the watermelon: Cut into cubes and remove any visible seeds.
Chill the cubes in the fridge for at least 1 hour, or freeze them on a sheet pan for 30–60 minutes to help the freeze set faster.
Drain excess juice (optional): If your watermelon is very watery, place cubes in a colander for 5–10 minutes. This keeps the final texture less icy.
Blend the base: Add watermelon, yogurt, lime juice, honey, vanilla, and salt to a blender. Blend until very smooth.
Taste and adjust sweetness or acidity as needed.
Decide your texture: For a soft-serve consistency, blend with partially frozen melon and serve right away. For a scoopable freeze, pour the mixture into a shallow, freezer-safe container.
Freeze and stir: Freeze the mixture for 2–3 hours, stirring with a fork every 30–45 minutes to break up ice crystals. This creates a smoother texture without an ice cream maker.
Add mix-ins (optional): During the final stir, fold in finely chopped mint or mini chocolate chips for extra flavor and texture.
Serve: When firm but scoopable, scoop into bowls.
Garnish with lime zest, fresh mint, or a few watermelon balls if you like.