Sun/Moon Data: Astronomy Engine | Weather: Open-Meteo
Use our Horizon Chart to see the current elevation of the Sun and Moon in 61 major cities. We track:
- Sunrise & Sunset: Plan your photography "Golden Hour".
- Moon Phases: Is it a Full Moon or New Moon tonight?
- Weather: Current temperature (Switch between Celsius/Fahrenheit) and sky conditions.
A: Calculating the exact time the sun will peek over the horizon requires precise geographical and astronomical data. The calculation depends heavily on your exact latitude and longitude, the current day of the year, and the Earth's elliptical orbit around the Sun. Algorithms use the "solar zenith angle" to determine when the upper edge of the Sun's disk appears and disappears relative to your specific location. Our tool processes these complex mathematical formulas in real-time to give you accurate local solar events.
A: Twilight is the period before sunrise and after sunset when the atmosphere partially scatters sunlight. It is divided into three phases based on the Sun's angle below the horizon. Civil twilight (0 to 6 degrees) is the brightest, allowing for most outdoor activities without artificial light. Nautical twilight (6 to 12 degrees) is darker; the horizon is still visible, making it crucial for sailors navigating by stars. Astronomical twilight (12 to 18 degrees) is the darkest phase, after which the sky becomes completely black, ideal for stargazing.
A: The Moon does not produce its own light; it reflects the light of the Sun. A moon phase refers to the portion of the Moon's illuminated half that is visible from Earth. As the Moon orbits our planet over a period of about 29.5 days (a lunar month), its position relative to the Earth and the Sun constantly changes. This creates the recognizable eight phases: New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Last Quarter, and Waning Crescent.
A: The length of daylight changes throughout the year because the Earth's axis is tilted at an angle of approximately 23.5 degrees. During summer in the Northern Hemisphere, that part of the Earth is tilted toward the Sun, receiving more direct sunlight and experiencing longer days. Six months later, it tilts away from the Sun, resulting in shorter days and the winter season. The equator experiences the least variation, maintaining roughly 12 hours of daylight year-round.