The long, cold December nights make this month one of the most interesting of the year for look at the skyThe Moon then reaches a very noticeable height in the northern hemisphere, while the Sun remains low above the horizon and the hours of daylight are reduced to a minimum.
In this context, the December lunar calendar It comes specially loaded: it includes the third and final supermoon of the year, two prominent meteor showers and the Winter Solsticeall concentrated into a few weeks that many fans already have marked on their calendars.
Cold full moon: the last supermoon of the year
At the lunar calendar for December 2025The full moon will arrive during the transition from the afternoon of the 4th to the early morning of the Friday December 5The full moon will reach its maximum at 00: 14 GMT (02:14 Spanish peninsular time), with the Moon located under the constellation gemini.
This full moon is traditionally known as cold moon or moon of the long nightsThese names are linked to the time of year when the cold intensifies in the Northern Hemisphere and the nights reach their longest point. a lot of cultures This moon was associated with the beginning of winter and with the time of retreat at home.
Moreover, it won't be just any full moon: it will be the third and last superluna out of 2025Because it occurs very close to the perigee (the point in the lunar orbit closest to Earth), the lunar disk will be seen something bigger and brighter than usual, especially when it appears or sets over the horizon.
Forecasts indicate that during the night of the 4th to the 5th we will enjoy a practically perfect moonAnd the following night, the sky will still appear almost round to the naked eye. In practice, those who look at the sky will have the sensation of contemplating two consecutive nights of full moon, something that always catches the attention of casual observers.
In the days leading up to the full moon, the Moon will share the spotlight with several bright planets. December 7, will be located in a very close conjunction with Jupiterwhich will appear as an intensely bright point next to it. A striking close approach is also expected to Saturn Around the December bridge, and at nightfall on those dates, a very characteristic image of the European winter sky can be seen.
Moon phases in December 2025: dates and times
The lunar cycle in December follows the usual pattern of about 28 daysbut each phase change occurs in a very precise momentdetermined by the geometry between the Sun, Earth, and Moon. For Spain and Western Europe, these are the key dates:
- Full moon (cold supermoon): Friday, December 5 at 00:14 GMT (02:14 in mainland Spain).
- Last quarterThursday, December 11 at 21:51 GMT (23:51 in mainland Spain), with the Moon in the constellation of Virgo.
- New Moon: Saturday, December 20 at 02:43 GMT (04:43 peninsular time), with the satellite in Sagittarius.
- First quarter: Saturday, December 27 at 20:10 PM GMT (21:10 PM in the peninsula), with the Moon in Aries.
At the beginning of the month, the Moon is already visible in advanced growing phaseThe moon is about 80% illuminated and approaching its full phase. As December progresses, the illumination changes, along with the moon's rise and set times, which affects both astronomical observation and ambient light on clear nights.
Between the full moon and the waning quarter, the disc will begin to appear slightly bulgedstill very bright during the December bank holiday weekend. Further on, near the miércoles 17The waning moon will be visible in the dawn sky, in a position very close to Mercuryforming an interesting combination for early risers.
Waning crescent: light in the second half of the night
El last quarter will occur Thursday December 11 at 21:51 GMT (23:51 peninsular time). At that moment, the Moon will be positioned in the Virgo constellation and will show illuminated the left half of its disk for observers in the northern hemisphere.
During this phase, the Moon rises a little later each day and it turns out It's easier to see it in the second half of the early morning. and the early morning hours. Nighttime visibility will gradually decrease, which is especially relevant for those who want to observe. showers of stars free from too much moonlight.
It is precisely during this part of the month that one of the great events of the annual astronomical calendar takes place: the Perseid meteor shower. GeminidsThis rain will be active from 4 to December 17, with a peak expected on the nights of 13 and 14and rates that can range around 120 meteors per hour under ideal conditions.
Since it is a waning moon, with an illuminated fraction that will continue to decrease, the Moonlight will be less annoying During the peak of the Geminid meteor shower, especially in the early hours of the morning, when the radiant is in the constellation of Gemini It is located very high in the sky.
New moon and total darkness for the Ursids
La new Moon will come Saturday December 20 at 02:43 GMT (04:43 in mainland Spain), when the Moon aligns between the Earth and the Sun in the constellation of SagittariusIn this configuration, the illuminated side of the satellite is oriented towards the Sun and The side visible from Earth remains in shadowTherefore, the Moon is invisible in the night sky.
This absence of moonlight creates some ideal dark conditions to observe meteors and faint celestial objects. It also coincides with the activity of the meteor shower. Ursids, popularly known as the Christmas rain.
The Ursids will be active from 17 to December 26, with its peak expected in the night of the 21th to the 22thAlthough its activity rate is more modest, around 5-10 meteors per hourThe absence of the Moon around those dates will allow us to clearly see the trails that appear to originate in the area of the constellation of Little Bear.
The temporal proximity between the new moon and the Winter Solstice It reinforces the symbolism of these days: the sky plunges into maximum darkness just as the calendar marks the beginning of the coldest season in Europe, but at the same time the days of daylight slowly begin to lengthen.
First quarter: the evening moon
El crescent quarter in December Saturday 27 at 20:10 GMT (21:10 peninsular time). At that moment, the Moon will be located in the aries constellation and will show the right half of the disc illuminated in the northern hemisphere.
In this phase, the Moon dominates the sunset sky and the early hours of the night. Each day it appears slightly higher above the horizon and with a greater percentage of its surface illuminated, moving towards the next full moon, which will fall in January.
At the end of the month, the satellite will pass relatively close to NeptunoAlthough this planet is not visible to the naked eye, a small telescope or astronomical binoculars allow it to be distinguished as a tiny bluish disc very faint, an interesting curiosity for those starting out in planetary observation.
The nights after Christmas, with the young moon tracing its characteristic "D" shape in the northern hemisphere sky, are often a cherished time for outings to the countryside and quiet observation after the most festive days.
Winter solstice: the shortest day and the longest night
Beyond the lunar phases, December marks a astronomical turning point with the solstice. In 2025, the December solstice will occur Sunday 21 at 16: 03 GMT (17:03 Spanish peninsular time), the moment when the Sun reaches its maximum decline towards the south.
In the Northern Hemisphere, that day translates to the shortest day and the longest night of the yearFrom then on, the days gradually gain a few minutes of daylight, although the feeling of winter persists for weeks due to the thermal inertia of the atmosphere and oceans.
The coincidence of this solstice with a new moon very near This makes the nighttime darkness especially intense around December 21st. Many European traditions link this period with renewal rituals, lighting of candles or bonfires and celebrations that symbolize the rebirth of light in the middle of the cold season.
Constellations and visible sky in December
The December sky offers some of the most recognizable constellations of the year, especially from Spain and the rest of Europe. On clear nights, the silhouette of Orion, with her unmistakable belt of three aligned stars, accompanied by figures such as Gemini, Taurus, Auriga and Perseus.
At this time, the so-called Winter Hexagon It reaches its maximum height around midnight, forming a broad asterism composed of some of the brightest stars in the sky. It's a great time to become familiar with the winter sky or to introduce newcomers to stargazing.
Those who have a small telescope or astronomical binoculars can take advantage of the nights around the waning crescent and new moon to locate open clusters and nebulae in the Taurus and Orion regions, as well as to distinguish without too much difficulty some of the visible planets of the solar system.
Geminids and Ursids: the meteor showers of the month
Among the meteor showers that occur at the end of the year, the Geminids They have gained a special reputation. It is one of the rains more active and reliable of the calendar, with activity rates that can exceed 120 meteors per hour at its peak, and can even reach values close to 150 under exceptional conditions.
In 2025, the Geminids will be active approximately from 4 to December 17, with a peak occurring on the nights of 13 al 14The meteors appear to originate from the area of the constellation of Gemini, visible for much of the night from the northern hemisphere, so the rain is especially favorable for European observers.
With the Moon in its advanced waning phase and a relatively low illuminated fraction At that time of year, the moonlight shouldn't ruin the observation, as long as you choose locations far from the Light pollution and the sky is clear.
The second notable rainfall of the month is the UrsidsA more modest rain, but with a strong symbolic component, as its peak usually coincides with the days leading up to Christmas. They will be active from 17 to December 26, with the peak between the night of 21 and the 22and a typical activity of 5 to 10 meteors per hour.
The radiant of this shower is located near the Little Bear, a circumpolar area of the sky from mid-European latitudes, making it possible to attempt observation at virtually any time of night, again with the added advantage thanks to the scant moonlight around the solstice.
Lunar calendar and self-care traditions
Beyond purely astronomical interest, the December lunar calendar It continues to have a significant influence on various traditional practices, from the biodynamic agriculture even certain habits of personal careAlthough science has not demonstrated a direct relationship between the phase of the Moon and hair growth, many people continue to use these dates as a symbolic reference.
Following the criteria of biodynamic agriculture, several types of days are distinguished depending on the position of the Moon with respect to the constellations and whether the star is rising or setting in its apparent orbit above the horizon. These patterns have been extrapolated, over time, to recommendations on haircuts and hair removal.
In the so-called root periodsWhen the Moon is in the terrestrial constellations and descending, it is believed that energy is symbolically concentrated at the base of plants. Applied to hair, this is associated with haircuts that They strengthen the root and structure of the hairSomething many people look for before seasonal changes.
Furthermore, the periods leaf These would correspond to the Moon in water constellations and ascending, moments in which tradition attributes a greater regenerative capacity to stems and leaves, and which some interpret as favorable dates for cuttings that prioritize a faster and more vigorous growth hair related.
Best days in December to get a haircut
Taking the guidelines of biodynamic calendars as a reference and adapting them to December 2025, several intervals are identified as being especially favorable for certain hair-related goals. It is important to emphasize that these are traditional criteria, without a solid experimental basis, but which many people follow as a kind of monthly ritual.
For those who want hair grow stronger and more resilientThe days associated with the aforementioned are recommended. root periodsThis month, those stretches are concentrated around mid-December, when the Moon travels through terrestrial constellations as it descends in its apparent path.
Specifically, they are noted as favorable for hair strengthening haircuts. From Friday the 12th to Monday the 15thpractically throughout the entire day in each case. These are dates when, according to biodynamic tradition, energy is focused on the root area, so hair cut on those days would appear denser and stronger as it grows back.
On the other hand, if the goal is for the hair grow faster and with a feeling of volumeThe recommended option would be the periods leafIn December 2025, these intervals are distributed between the beginning and end of the month, coinciding with the Moon in water constellations and ascending.
The key dates for this purpose would be all day Monday 1 (including the early hours of Tuesday) and, towards the end of the month, the Saturday afternoon, the 27th from 16:00 PM onwards, in addition to all day Sunday the 28th and Monday morning, the 29th until noon. Many hair salons that follow these types of schedules mark these days as good times to renewal cuts prior to the end-of-year holidays.
Recommended days for hair removal according to lunar tradition
With regard to the hair removalTraditional logic is the exact opposite of haircutting. It seeks out times when, symbolically, energy moves away from the surface and the growth impulse is reduced. Again, there is no conclusive scientific evidence, but many people use these dates as a simple guideline.
The days that coincide with the so-called flower daysWith the Moon descending in air constellations, these are considered the most auspicious for slow hair growthIn December 2025, these sections will be concentrated into two distinct blocks.
The first one covers all Saturday 6th starting in the early morning, followed by all day Sunday the 7th until late at night. The second block is around the middle of the month: it is especially recommended Tuesday the 16th throughout the day and Wednesday morning, the 17th until midday as suitable times for waxing sessions.
In any case, the actual appearance of hair and body hair will depend much more on factors such as the genetics, diet, stress, or the products used in the daily routine rather than the specific phase of the Moon. The lunar calendar acts here more as a symbolic and organizational framework than as a tool with proven effectiveness.
El lunar calendar for December 2025 It's shaping up to be a particularly rich month for lunar phenomena: a cold supermoon visible for two nights, a complete and well-distributed lunar cycle, two notable meteor showers, and the winter solstice marking the start of the coldest season in Europe. Those who enjoy gazing at the moon can combine the sky observation With these traditional uses in agriculture and personal care, taking advantage of the fact that the long nights leave plenty of time to both look up and plan the day-to-day with an eye on the sky.
