Lunar calendar · computed live
For aurora hunters the Moon is a lamp that lights the snow; for deep-sky imagers it is the enemy. Either way, you plan around it. Below is a calendar for this month and next, calculated in your browser from orbital elements — no tables downloaded, nothing to go out of date.
The panel shows the Moon’s phase at this moment, the share of its disc that is lit, and its age — days since the last new Moon. A full cycle, new Moon to new Moon, takes 29.53 days on average, but any single month can run several hours longer or shorter because the Moon’s orbit is an ellipse that gets tugged around by the Sun.
The phase is computed from the difference between the Moon’s and the Sun’s ecliptic longitudes, using a short version of the series in Jean Meeus’s Astronomical Algorithms. It agrees with published phase times to within about half an hour, which is far better than our weather forecasts.
Times on this page are shown in your local time zone.
Each day shows the Moon as it looks at 21:00, with the percentage of the disc lit. Days with a principal phase are tinted and carry the exact time. Today is outlined.
Things we learned the slow way, mostly in the cold.
Geometry
A full Moon sits opposite the Sun, so in December it takes the summer Sun’s path: high in the south at midnight, and up for most of the day as well. In midsummer it is the other way round — the June full Moon barely clears the southern horizon, and some years it does not rise at all here. Our best lunar close-ups are all from November to February.
2024 – 2025
Every 18.6 years the tilt of the Moon’s orbit lines up with Earth’s, and the Moon swings as far as 28.5° north and south of the celestial equator. Any declination above 22.6° makes it circumpolar from Sodankylä. Around the standstill in 2024 and 2025 we watched the Moon circle the sky for two days without setting, and two weeks later not rise at all.
Exposure
For a sunlit full Moon, try f/11 with a shutter speed of one over your ISO: ISO 200 at 1/200 s. Open up one or two stops for quarters and three for thin crescents, where the light is grazing. For real surface detail, record video with a small planetary camera and stack the sharpest few hundred frames — it beats any single exposure.
Ice crystals
Below about −20 °C the air fills with tiny ice crystals. A bright Moon then grows a 22° halo, sometimes with paraselenae — moon dogs — on either side, and the lights of Sodankylä send vertical light pillars into the sky. A 14 mm lens covers the whole halo. Breathe away from the camera, or the front element frosts in seconds.
Spring evenings
Two or three days after new Moon, the dark part of the disc glows faintly with sunlight reflected off Earth. In March and April the evening crescent stands steeply over the western horizon, which suits us. Expose for the dark side (two to four seconds at ISO 400 on a telephoto) and blend with a short frame for the crescent.
Eclipses
Lunar eclipses visible from Lapland tend to happen near the horizon. On 7 September 2025 the Moon rose already in total eclipse over Kemijärvi; we had scouted an east-facing shore the week before with a compass app. Check the azimuth of moonrise, find open water or a fell edge in that direction, and arrive an hour early.
Moon and aurora. A quarter to half Moon is our favourite aurora light: bright enough to show snow and trees without a long exposure, dim enough that the aurora still pops. A full Moon flattens faint displays; a new Moon gives you black silhouettes and the faintest arcs.