Can You See Hawaii from San Diego? The Science Behind the Answer

No. Hawaii is approximately 2,500 miles (4,000 km) from San Diego. Two physical realities make visibility impossible:

1. Earth's Curvature: The horizon from sea level is only about 3 miles away. Even from San Diego's highest coastal points (~500 ft), the horizon extends to roughly 27 miles—nowhere near 2,500.
2. Elevation Limits: Hawaii's highest peak, Mauna Kea (13,802 ft), would need to be viewed from an impossible height to clear the curvature bulge between the two locations.

You can, however, see Hawaii from the International Space Station—or in photos taken from there.