Dice watermelon into small ½-inch cubes. Keep uniform.
Remove excess seeds. Pat cubes dry with paper towels.
Cut jalapeños in half. Remove seeds and membranes. Dice finely.
Finely dice red onion.
Chop cilantro.
Combine watermelon, jalapeños, onion, and cilantro in large bowl.
Add lime juice, zest, honey, salt, and pepper.
Gently toss until well combined.
Taste. Adjust seasoning as needed.
Let sit 10 to 15 minutes for flavors to meld.
Transfer to serving bowl.
Serve with chips, on grilled meat, in tacos, or with lime wedges.
Serve immediately or refrigerate up to 4 hours.