Celestial latitude measures the north and south height of a planet to the ecliptic plane (given by the apparent motion of the Sun, which therefore has a geocentric latitude of 0°)
From the interpretive point of view, most modern authors assign a somewhat subordinate role to the aspects of latitude. Indeed, planetary orbits except that of Pluto – which has a maximum eccentricity of about 17 ° – lie roughly on the ecliptic plane. In this regard, we have already mentioned the greater interest that has arisen today on declination aspects. In traditional astrology – apart from the consideration given to the variation of solar declination at the origin of seasonal phenomena – the proximity of classical planets to the plane of terrestrial revolution has always played in favour of the aspects in latitude relating to the ecliptic, if even in a marginal way with respect to the aspects in longitude.
However, problems arise in applying latitude values. Excluding Pluto, all the other planets are within a maximum band of 7° north and south of the ecliptic. Mercury may be at the limit of this belt, but Mars is only 1° 19 ‘away from the ecliptic and Uranus, at 0° 8′, lies practically on its plane; this poses problems in the calculation of tolerance orbits forming an aspect, with the risk of having many planets almost always in close contact. The general consideration on the use of the parallels of latitude is to note their position north or south to the ecliptic, assigning a value of strength or weakness on specific aspects of the chart. Otherwise, the considered orbit is one degree (for classical planets).
Ptolemy, in his Centiloquium, dedicates aphorism LIII to the theme:
The Lords of the Geniture's of lean men have no latitude, but of fat men they have; if the latitude be south, the Native will be nimble; if North, more sluggish.
The Master of the nativity does not mean the planet that rules the sign of the Ascendant, as is currently customary. The method used for this calculation by Porphyry in his introduction to the Ptolemy’s Tetrabiblos states that the Master of the nativity is the planet domiciled in the sign of the Sun, of the Moon or the Ascendant, chosen based on its strength in the birth chart.
On the contrary, in horary astrology, it is believed that a planet strengthens the expression of a judgment the higher it is in the north latitude, while it weakens the further it goes down to the southern latitude. The planet or planets considered are the ones that govern the question posed.