Sixty degrees, and why the orb is tighter
A sextile is a sixth of the circle. The orb allowed here is five degrees rather than the seven of a trine or the eight of a conjunction, because the aspect is considered weaker and a generous orb would let it appear almost everywhere.
That tighter allowance has an obvious consequence. The window is ten degrees wide, and the Moon covers ten degrees in about eighteen hours. The sextile occurs twice per lunar circuit, so the total is roughly a day and a half in every twenty seven, which lands somewhere near one birth in eighteen. It is less common than the trine or the square purely because of the narrower orb.
As with the other Moon to Uranus contacts, Uranus is effectively parked. It moves about four minutes of arc a day and is retrograde for close to half the year, which makes a natal retrograde Uranus entirely ordinary and irrelevant to this aspect. Everything about the timing belongs to the Moon.
What the tradition asks of a sextile
The Moon is instinct, habit and the conditions under which a person can rest. Uranus is the break with an established pattern. A sextile links signs of compatible elements, fire with air or earth with water, and is read as a connection that works when it is engaged and lies dormant when it is not.
Applied to this pair, the description is a capacity for changing your mind and your circumstances without much internal cost, available on request. Where the square makes the person restless whether they like it or not, the sextile makes flexibility a tool they can pick up. People with it are often described as good in unfamiliar situations, provided they choose to enter one. Left alone, the aspect can pass an entire life unused, and nothing in the chart will complain about that.
This is why sextiles are so often skipped in general readings. They describe a possibility rather than a behaviour, and possibilities do not make good copy. It also means the aspect ages differently: it tends to be more visible in people who have deliberately put themselves in changeable situations than in people who have not.
Sign, house and orb in a narrow aspect
Because the orb is only five degrees, the range between a tight sextile and a wide one is small, and the difference in strength is correspondingly compressed. Inside one degree the aspect is worth reading. At four or five it barely registers, and it is fair to leave it out of a summary of the chart entirely.
Element pairing sets the flavour. An earth to water sextile reads as practical adaptability, a willingness to reorganise the material conditions of life without drama. A fire to air sextile reads as mental and social mobility, comfort with new people and new arguments. Neither of those is a prediction, only a description of where the flexibility is most easily reached.
Houses do the rest. A sextile involving the fourth or the tenth points the capacity at home or at public role. One between the third and the fifth is smaller and more everyday. As always the houses require a birth time, and the Moon changes house about every two hours, so an approximate time is not good enough here.
How much attention this deserves
Honestly, less than the hard aspects. A sextile with nothing else supporting it is background, and the site's position is that saying so is more useful than manufacturing significance. If Moon sextile Uranus is the only contact between these two bodies in your chart and it sits at four degrees, it is a footnote.
It becomes worth reading in two situations. The first is a tight orb, under a degree or two, where the description above tends to be recognisable. The second is when it supports something harder, for instance a chart with a difficult Moon that has this sextile as its one route to flexibility. In that case the small aspect is doing real work and should be read as part of the pattern rather than on its own.
The check above will tell you which of those you are looking at. It reports the orb, both signs and both houses, and with a sextile the orb is the first thing to look at.
Questions people ask about this
Why is the sextile orb only five degrees?
Sextiles are treated as the weakest of the five major aspects, so a narrower orb keeps them from appearing in almost every chart. On this site the allowance is five degrees, against seven for a trine and eight for a conjunction.
How common is Moon sextile Uranus?
Near one birth in eighteen. The aspect happens twice per lunar circuit but each pass is only about eighteen hours wide, which makes it less frequent than the trine or the square despite occurring just as often.
What is the difference between a sextile and a trine here?
A trine is read as an ability you already have and may never develop. A sextile is read as one that stays dormant until it is taken up. The trine also carries a wider orb, so it usually reads more strongly.
Does a sextile do anything if I ignore it?
In the traditional reading, very little. That is the defining property of the aspect. It describes a capacity that becomes visible when circumstances or choices call on it, and otherwise sits quietly in the chart.
Is my Uranus retrograde a problem for this aspect?
No. Uranus spends around five months of each year retrograde, so most people are born with it that way. Its motion is far too slow to affect an aspect that opens and closes inside a single day.
When is this aspect worth reading closely?
When the orb is inside a degree or two, or when the chart has a difficult Moon elsewhere and this sextile is the one flexible contact it makes. Otherwise it is reasonable to treat it as a background note.