Bring a large pot of water to a rolling boil and carefully add the fresh corn cobs. Boil for 1½ to 2 minutes until tender but crisp. Remove and cool in ice water.

While the corn cools, halve the tomatoes and finely chop the red onion and cilantro. Place in a large mixing bowl.

Once cool, cut kernels from corn cobs and add to the bowl. Stir gently to mix all the ingredients.

Squeeze lime juice over the salad, season with salt and pepper, and toss to coat evenly.

Cover and refrigerate for at least 1 hour to meld flavors.

Dice avocado just before serving and gently fold into the salad. Serve with lime wedges.