Reaching up to 100 feet long in some parts of the world, they are truly an amazing sight to see. Named for the blue glow that appears when they are near the surface, not because of their actual color which is gray. Listed as an endangered species with a worldwide population estimated to be from 10,000 to 20,000, the North-Eastern Pacific population is the largest concentration with approximately 2,000-3,000 individuals which makes Southern California easily the best place in the world to see blue whales. They are considered one of the summer species of whales seen off the coast of Orange County along with humpback, fin, and minke whales. The reason they show up here along Southern California is to feed on vast amounts of krill, the duration of blue whale season for us here all depends on how long we have krill in the water, we can sometimes see the same blue whales stick around for weeks at a time and can sometimes see blue whales pass right through the area without stopping. June holds the best odds of seeing them here although we do have sightings of blues throughout the summer but every year tends to vary based on the abundance of krill, if we had lots of wind and underwater upwelling prior to June, there's a good chance there will be lots of krill for them that was pushed up by the underwater canyons/currents.