The general understanding is that the sun rises in the east, but the exact point on the horizon changes daily. This constant shift is governed by the Earth’s orbit and tilt. Hawaii’s unique position near the equator gives it a distinct seasonal pattern.
The Basic Direction and Why It Varies
The sun generally appears to rise in the east because the Earth rotates on its axis from west to east. If the Earth’s axis were perfectly perpendicular to its orbital plane, the sun would rise exactly due east every single day.
The Earth’s axis is actually tilted about 23.44 degrees relative to its orbit. This tilt is the fundamental reason the sunrise direction varies throughout the year. As the Earth travels along its yearly path, the Northern Hemisphere is sometimes tilted toward the sun and sometimes tilted away.
The sun rises exactly due east only twice a year, during the spring and autumn equinoxes. For the rest of the year, the sun’s rising point shifts along the horizon. During the Northern Hemisphere’s summer, the sun rises north of true east, and during the winter, it rises south of true east.
Hawaii’s Position and Seasonal Shifts
Hawaii is located at a low latitude, with the main islands situated between approximately 19° and 22° North. This places the islands within the tropical zone, just south of the Tropic of Cancer. This low latitude is the primary factor that minimizes the seasonal movement of the sun’s rising point compared to other locations.
The horizontal angle of the sunrise, known as the azimuth, changes much less dramatically in Hawaii than it does in locations further north, such as Alaska or Maine. In higher latitudes, the sun’s path changes drastically, leading to long summer days where the sun rises far to the northeast and short winter days where it rises far to the southeast.
Because Hawaii is close to the equator, the sun’s declination (its angular distance north or south of the celestial equator) has a smaller effect on the sunrise direction. The sun is always relatively high in the sky, and its rising point oscillates over a comparatively narrow arc on the eastern horizon. The tropical location provides a consistency in the sun’s daily path not seen in most of the continental United States.
Practical Guide to Sunrise Extremes
To observe the full range of the sunrise direction in Hawaii, one must track the extremes occurring at the solstices. The sun rises at its farthest northern point on the horizon around the Summer Solstice (June). Conversely, the sun rises at its farthest southern point around the Winter Solstice (December).
For a central location like Honolulu (21.3 degrees North latitude), the sunrise azimuth ranges from 70 degrees (north of east) in the summer to 110 degrees (south of east) in the winter. True east is 90 degrees. This means the sun’s rising point shifts about 20 degrees north and 20 degrees south of true east. This relatively narrow 40-degree range is a direct result of the islands’ tropical latitude.
This annual shift is important for choosing a sunrise viewing location. To see the sun rise over the ocean from an east-facing beach near the Winter Solstice, you would need to look slightly more toward the south than near the Summer Solstice. Knowing these directional limits helps residents and visitors plan their viewing experiences throughout the year.