When does the sun reach zenith as seen from Los Angeles?

The sun reaches zenith as seen from Los Angeles on May 25 and July 17 of every year. This is because Los Angeles is located at approximately 34 degrees north latitude, and the sun's declination (the angle between the sun's rays and the Earth's equatorial plane) is 23.5 degrees north at its peak. This means that on these two days of the year, the sun will be directly overhead at noon, and its rays will be perpendicular to the Earth's surface.