Cook bacon in a skillet over medium heat until crisp. Drain on paper towels and crumble.
Whisk mayonnaise, sour cream, vinegar, sugar, Dijon, salt, and pepper in a large bowl until smooth.
Add peas, red onion, cheddar, and dill to the bowl.
Fold gently until the peas are evenly coated with dressing.
Chill to let flavors meld if time allows. Keep bacon separate so it stays crunchy.
Sprinkle bacon over the salad and toss just before serving.