Moon phase tonight: live lunar data for your city.
Looking up at the sky and wondering what the Moon is doing tonight? You want a few specific things: the current phase name (new, waxing crescent, first quarter, waxing gibbous, full, waning gibbous, last quarter, waning crescent), the illumination percentage as a number, when the Moon will rise above your horizon, when it will set, and roughly how high it gets at peak. Lumara gives you all of that for your location.
How Lumara computes moon phase data.
Lumara uses Jean Meeus's Astronomical Algorithms, the same math used by professional observatories. Given your location and the current timestamp, the engine computes lunar phase, illumination percentage, rise and set times, altitude, and distance to about a minute of accuracy. The calculations work offline since they are pure math, no API call needed. Open the app once with a signal and you can use it on a plane or in the woods.
What does each phase mean?
Phase tracks the angle between the Sun, the Moon, and you. At new moon the Moon sits roughly between you and the Sun, so the lit side faces away and you see nothing. At full moon the Moon is opposite the Sun in your sky, so the entire visible face is lit. Waxing means the lit fraction is growing toward full. Waning means it is shrinking back toward new. The cycle from one new moon to the next is about 29.53 days.
Why illumination percentage matters.
The percentage is the fraction of the visible disk that is currently lit. At full moon it is 100%. At new moon it is 0%. Half illumination does not happen exactly at first or last quarter, because the terminator (the edge between lit and dark) is a curved line on a sphere, but the practical answer is close enough. Photographers and astronomers care about this number because it controls how much ambient light the Moon throws.
Rise, set, and altitude for your city.
The Moon rises and sets at different times every night, and the timing depends on your latitude. Lumara supports 200+ cities out of the box, and the underlying engine works for any latitude and longitude. You see the next rise time in your local timezone, the next set time, the current altitude in degrees above the horizon, and the current distance to the Moon in kilometers. The distance varies between about 357,000 km (perigee) and 405,000 km (apogee) over a roughly month long cycle.