The position, stated plainly
Taking noon across the years from 1930 to 2035, the Sun on 14 February has been between about twenty four and three quarters and twenty six degrees of Aquarius. The window is narrow because the leap day keeps the calendar and the orbit in step, snapping the date back roughly a day every four years to cancel the annual quarter degree creep.
Aquarius is fixed air with Saturn as its classical ruler and Uranus as the modern one. This birthday sits five sixths of the way through the sign, about three and a half days before the Sun crosses into Pisces, so the sign is settled without being anywhere near a boundary.
Your own year decides where inside that window the Sun falls. A birth in a leap year sits near the lower edge, and the figure creeps up through the three years that follow before the next leap day resets it.
The saint's day has no bearing on the chart
The association of this date with romance comes from the medieval feast calendar and later from print culture, not from any celestial event. Nothing in the tradition marks the twenty fifth degree of Aquarius as being about attachment, and no technique in use takes the calendar date as an input separate from the position it corresponds to.
It is worth saying because the two things are often quietly blended. A chart drawn for this date reads the same as a chart drawn for any other, and the placements are what they are regardless of what the day is called.
The same applies to the numerology often attached to the date. Whatever is read into the numbers, it comes from a different system with different rules, and it does not enter the astronomical calculation at any point.
The decan is the layer that distinguishes it
Twenty five degrees falls in the third decan of Aquarius, which runs from twenty degrees to thirty. The decans are an old Egyptian device for dividing the night, later fitted with planetary rulers, and in the Chaldean order this band is assigned to the Moon.
Tradition treats the Moon decan as the part of Aquarius that turns its detachment inward, toward memory and the settled circle rather than the wider cause. That is inherited reading rather than measurement, and other schemes assign the same ten degrees to a different planet, which shows how much of it is convention.
What is left undetermined
The Moon changes sign every two and a half days or so, so on this date it will be in one of two signs depending on the hour and the time zone. Across different years it has occupied all twelve, and there is no link at all between the calendar date and the lunar sign.
The rising sign is entirely open, since it depends on the exact minute of birth and on how far north or south that birth happened. The widget above works out your precise solar degree from your own details and reports the distance to the nearest sign boundary, which here will be a little over three days.
That margin means the noon default used when a birth time is unknown cannot put the sign wrong here, though it does leave the degree loose by up to half a degree.
Questions people ask about this
What sign is 14 February?
Aquarius in every year. The Sun does not reach Pisces until around 18 or 19 February, so this date is never in doubt.
Does the romantic association mean anything astrologically?
No. It comes from the feast calendar and later custom. No technique in the tradition takes the name of the day as an input, only the position of the Sun.
What degree of Aquarius is this?
About twenty five degrees, varying by roughly a degree and a quarter across the last century at noon. The widget above gives the figure for your own birth.
Which decan and which ruler?
The third decan of Aquarius, from twenty to thirty degrees, assigned to the Moon under the Chaldean sequence.
How close is this date to Pisces?
Around three and a half days short of the boundary, which is far enough that no year in the modern calendar moves it across.
Is a shared birthday the same as a shared chart?
Not remotely. Two people born on the same date can share the Sun to within a degree and differ on the Moon, the Ascendant and every house cusp.