Waning Gibbous Moon: Why It Rises After Dark and How It Looks from Cape Town

A few nights after the full Moon, the Moon starts rising later. It comes up after sunset, climbs high after midnight and is still in the sky when the Sun rises. The disk is still more than half lit, but it is shrinking. This is the waning gibbous.

This guide explains what a waning gibbous Moon is, where it sits in the 29.5-day cycle, when it rises and sets, and why it looks different from Cape Town, South Africa, than from the Northern Hemisphere. At the end you can try it in the Moon Dial.

What a waning gibbous Moon is

The U.S. Naval Observatory describes the waning gibbous as the phase when the Moon appears to be more than one-half but not fully illuminated by direct sunlight, with the lit fraction of the disk decreasing. NASA's Space Place says waning means getting smaller, and that the phase sits between a full Moon and a half Moon. The Naval Observatory gives the range in numbers: during the gibbous phases the percent lit is between 50 and 100.

NASA's phase notes explain what is going on. The Moon is heading back toward the Sun in its orbit, so the opposite side of the disk now catches the light, compared with the waxing phases. The lit side seems to shrink, but NASA stresses that the Moon's orbit is simply carrying it out of view from our perspective. The Sun still lights half of the Moon, as it always does. We just see less of that lit half each night.

Where it sits in the cycle

The waning gibbous follows the full Moon and comes before the last quarter, which NASA also calls the third quarter. The Naval Observatory calls the gibbous phases intermediate phases, and each one lasts about a week between the primary phases.

The cycle takes about 29.5 days, and the Moon's age is the number of days counted from the new Moon. The full Moon sits halfway, at about 14.8 days. The Naval Observatory says the last quarter occurs when the Moon is three-quarters of the way around its orbit from new Moon, which is about 22.1 days. So a waning gibbous Moon has an age between about 14.8 and 22.1 days. The middle is about 18.5 days, the age drawn below.

In the drawing, sunlight comes from the right. The Moon has moved past the left side of its orbit, the full Moon position, and is heading back around toward the Sun. The Naval Observatory defines the primary phases by how far the Moon's ecliptic longitude, a position measured along the plane of Earth's orbit, is ahead of the Sun's. That difference is 180 degrees at full Moon and 270 degrees at last quarter. A waning gibbous Moon lies in between.

When it rises and sets

NASA gives a rule of thumb for most latitudes. A waning gibbous Moon rises at night, after sunset, and sets in the morning, after sunrise. NASA adds that in this phase the Moon rises later and later each night. NASA's visualization team gives the same pattern in a short caption: it rises after sunset, is high in the sky after midnight and is still visible after sunrise.

The table shows the waning gibbous between its neighbors.

Because it sets after sunrise, this Moon can still be up in daylight. NASA says the Moon is up as much during the day as at night, though you may not notice it as easily when the Sun is also up. These times are patterns, not timetables. NASA says the time the Moon is visible depends on its phase, the time of year and your location, so for exact moonrise and moonset times you should check local predictions.

Seeing it from Cape Town

Everyone on Earth sees the same phase at the same time. The Naval Observatory says that for practical purposes the phases do not depend on where you observe the Moon, because all the phases occur at the same time regardless of the observer's position. NASA adds that people north and south of the equator see the Moon's current phase from different angles. If you traveled to the other hemisphere, the Moon would be in the same phase but would look upside down compared with what you are used to.

Cape Town is in the Southern Hemisphere. A NASA Earth Observatory image of the Cape Town area is located at 34.2 degrees south latitude, so the city is well south of the equator. A waning gibbous Moon there looks turned by half a turn compared with the Northern Hemisphere.

NASA's own example is a waning crescent on March 8, 2021. In the Northern Hemisphere the crescent appeared on the left side of the Moon, and in the Southern Hemisphere it appeared on the right. The same flip applies to the gibbous phase and to the whole cycle. The University of Hawaiʻi's science education program notes that from the Northern Hemisphere the sequence from waxing to waning appears in a D, O, C order, while observers in the Southern Hemisphere see the opposite order, C, O, D. NASA's visualization team also publishes a south-up version of its Moon images. A south-up image is the north-up image flipped horizontally and vertically, which equals a 180-degree rotation.

In the figure, the Northern Hemisphere Moon is lit on the left. The Southern Hemisphere Moon, the one a viewer in Cape Town sees, is lit on the right.

Common mistakes

• Reading the lit side without the hemisphere. From Cape Town the lit side of a waning Moon is on the right. In the Northern Hemisphere it is on the left.
• Mixing it up with a waxing gibbous. Both are more than half lit. The waning one is shrinking and rises at night, after sunset. The waxing one is growing and rises in the afternoon.
• Looking for it only at night. It sets in the morning, after sunrise, so it can still be up in daylight.
• Thinking the Moon itself shrinks. The Sun always lights half of the Moon. NASA says the lit side only appears to shrink as the orbit carries it out of our view.
• Calling it full because it looks round. The lit share changes slowly near full Moon. The Naval Observatory says it is 97 to 99 percent lit on the night after full Moon and 93 to 97 percent two days after, so the first nights of this phase can pass for full.
• Expecting one exact age. The phase lasts about a week, so the dial accepts a range of ages.

Try it in the instrument

Open the Moon Dial and set the sky to a waning gibbous Moon as seen from Cape Town, South Africa. Two things must match: the age and the view. The target age is about 18.5 days, roughly midway between full Moon (about 14.8 days) and last quarter (about 22.1 days). The view is the Southern Hemisphere, because Cape Town lies south of the equator. The dial starts in the Northern Hemisphere view, so you need to switch it. If the age is right but the view is not, the dial tells you to switch the view and lock in again.

In the Southern Hemisphere view, a waning gibbous Moon is more than half lit with the bright edge on the right. The phase lasts about a week, so the dial accepts a range of ages. Go too far one way and the dial reads full Moon. Go too far the other way and it reads last quarter. On Bronze the dial prints the phase names. On Silver you only get tick marks. On Gold you get no marks, so you have to read the picture: more than half of the disk lit, with the bright edge on the right in the Southern Hemisphere view.

Questions people ask

What time does a waning gibbous Moon rise?

At night, after sunset, according to NASA. It rises later each night and sets in the morning, after sunrise. Exact times depend on the season and your location, so check local predictions.

Which side of a waning gibbous Moon is lit in South Africa?

The right side. NASA says people north and south of the equator see the same phase from different angles. Its example shows a waning crescent on the left in the Northern Hemisphere and on the right in the Southern Hemisphere, and the University of Hawaiʻi says the whole sequence of shapes reverses in the south.

How many days does a waning gibbous last?

It starts just after the full Moon, at an age of about 14.8 days, and ends at the last quarter, at about 22.1 days. The Naval Observatory says each gibbous phase lasts about a week.

Why does the lit part get smaller if the Moon is always half lit?

Because we see less of the lit half each night. NASA says the lit side only seems to shrink as the Moon's orbit carries it out of our view.

Sources

• Moon Phases, NASA Science. https://science.nasa.gov/moon/moon-phases/. Opened November 9, 2026.
• Phases of the Moon and Percent of the Moon Illuminated, U.S. Naval Observatory, Astronomical Applications Department. https://aa.usno.navy.mil/faq/moon_phases. Opened November 9, 2026.
• Top Moon Questions, NASA Science. https://science.nasa.gov/moon/top-moon-questions/. Opened November 9, 2026.
• What Are the Moon’s Phases?, NASA Space Place. https://spaceplace.nasa.gov/moon-phases/en/. Opened November 9, 2026.
• Moon Phase and Libration, 2026 South Up, NASA Scientific Visualization Studio. https://svs.gsfc.nasa.gov/5588/. Opened November 9, 2026.
• Weird Science: Phases of the Moon, Exploring Our Fluid Earth, University of Hawaiʻi at Mānoa (Curriculum Research & Development Group). https://manoa.hawaii.edu/exploringourfluidearth/physical/tides/tide-formation-gravitational-pull/weird-science-phases-moon. Opened November 9, 2026.
• Cape Town, South Africa, NASA Earth Observatory (hosted on NASA Science). https://science.nasa.gov/earth/earth-observatory/cape-town-south-africa-4665/. Opened November 9, 2026.

We opened each source ourselves on the date shown. The drawings are our own and were checked against the numbers in these sources.

Read next

• Full MoonThe full Moon is the Moon facing the Sun's opposite side of the sky.
• Last Quarter MoonAt last quarter the Moon shows half its disk lit, and the lit part is shrinking.