In a large mixing bowl, combine the fresh corn, red bell pepper, cucumber, cherry tomatoes, avocado, red onion, and cilantro.
In a small bowl, whisk together the lime juice, olive oil, salt, black pepper, and chili powder (if using).
Pour the dressing over the salad and gently toss to combine, being careful not to mash the avocado.
Let the salad sit for about 10 minutes at room temperature to allow the flavors to meld.
Serve immediately or refrigerate for up to 2 hours before serving for a chilled option.