Waning Crescent Moon: The Last Thin Curve of the Cycle, Lit on the Left in the North

A waning crescent is a thin curve of light that rises in the early morning and shrinks a little more each night until the Moon disappears at New Moon. It lasts about a week. It rises before the Sun, which makes it the early-morning twin of the waxing crescent.

This guide explains what a waning crescent is, where it sits in the 29.5-day cycle, when it is in the sky and which side is lit in each hemisphere. At the end there is a short task in the Moon Dial.

What a waning crescent is

The U.S. Naval Observatory defines the waning crescent as the phase when the Moon appears to be partly lit by direct sunlight, but less than one-half lit, and the lit fraction of the disk is decreasing. NASA's Space Place says that waning means getting smaller. During the crescent phases the share of the disk that is lit is between 0 and 50 percent, the Naval Observatory adds.

NASA's Moon Phases page describes the same moment from the orbit. The Moon is nearly back to the point where its day side faces the Sun directly, so all that we see from Earth is a thin curve. The Naval Observatory says what follows: after the waning crescent comes New Moon, which starts the next 29.5-day cycle.

It helps to remember what is happening on the Moon itself. NASA's Top Moon Questions page says that during a crescent the half of the Moon that faces Earth is mostly in shadow, and the far side is mostly sunlit. The visible crescent is the only part of the near side that is having daytime. So the rest of the Moon is still there. The near side is mostly in night, and the sunlit far side is out of view.

Where it sits in the cycle

The cycle of phases lasts about 29.5 days on average, and the Moon's age is the number of days counted from New Moon. The waning crescent comes after last quarter, at an age of about 22.1 days, and before the next New Moon. The Naval Observatory says each crescent and gibbous phase lasts about a week between the primary phases, and 29.5 minus 22.1 is about 7.4 days.

In the Moon Dial, the name Waning Crescent covers ages from about 23.2 up to about 28.5 days, because the dial calls an age a primary phase when it lies within a day of the exact time. The drawing below shows an age of 26 days, close to the middle of the stretch. The midpoint of 22.1 and 29.5 is about 25.8.

In the drawing, sunlight comes from the right. The Moon is in the lower right of its orbit, close to the Sun's side, so the half that faces Earth is mostly dark. The angle between the Sun and the Moon in the sky is the key. The Naval Observatory says the quarter phases occur when the two are about 90 degrees apart, and that New Moon occurs when they are quite close together. During the waning crescent, that gap closes from about 90 degrees toward nothing.

When it is in the sky

NASA gives a rule of thumb for most latitudes: the waning crescent Moon rises in the very early morning, before sunrise, and sets in the afternoon, before sunset. NASA's Scientific Visualization Studio gives a picture caption for it: low to the east before sunrise. The Moon is therefore a pre-dawn sight, and it is gone long before the evening.

The table below follows moonrise through the last week of the cycle. The words come from NASA. The times come from a chart on the University of Iowa's lab page, which treats sunrise as 6 a.m. and sunset as 6 p.m. Each step moves moonrise about three hours later, which fits NASA's remark that the Moon rises later and later each night. At New Moon the Moon rises with the Sun.

The same chart lists the waning crescent as highest in the sky at 9 a.m. That is daytime, and NASA explains why a thin Moon is hard to find then: the Sun is up, and the crescent phases show only a little of the Moon's bright side. So plan to look in the hours after moonrise while the sky is still dark.

If the sky is clear, you may see more than the crescent. NASA says that during a crescent phase in the twilight or at dawn, you can sometimes see the dark part of the Moon glowing faintly. The light comes from sunlight reflecting off Earth, an effect called earthshine. NASA also stresses that these timings are patterns for most latitudes. For exact moonrise and moonset times, check local predictions.

Which side is lit

NASA's Space Place says that in the Northern Hemisphere we see the waning crescent as a thin crescent of light on the left. The waxing crescent is on the right. If you want to compare the two, read the guide to the waxing crescent Moon.

Everyone on Earth sees the same phase, NASA says, but people north and south of the equator see it from different angles. If you travel to the other hemisphere, the Moon is in the same phase but looks upside down compared with what you are used to. NASA's example is a waning crescent on March 8, 2021. Seen from the Northern Hemisphere, the crescent was on the left side of the Moon. Seen from the Southern Hemisphere, it was on the right.

Common mistakes

• Looking for it in the evening. A waning crescent has set by then. NASA says it sets in the afternoon, before sunset. A thin crescent low in the evening sky just after sunset is a waxing crescent.
• Reading the curve's direction without the hemisphere. The same crescent is on the left in the north and on the right in the south.
• Calling the rest of the Moon dark. The Moon is always half lit by the Sun. During a crescent, the lit half is mostly the half we cannot see.
• Expecting one exact age. The waning crescent lasts about a week, so the game accepts a window of ages.
• Searching in the afternoon. The crescent may still be up then, but NASA says the Moon is harder to see when the Sun is up. The early morning hours are the better time.

Try it in the instrument

Open the Moon Dial and set the sky to a waning crescent Moon. The target is an age of about 26 days, near the middle of the stretch between last quarter (about 22.1 days) and New Moon (about 29.5 days). The request asks for the Northern Hemisphere view, which is where the dial starts. In that view the lit edge of a waning crescent is on the left. If you switch to the Southern Hemisphere view, the age can be right while the view is wrong.

On Bronze, the read-out under the dial gives the age, the percent lit and the phase name, and the ring prints the phase names. On Silver you get the age and the percent lit, but no name. On Gold the read-out says only how much is lit and which edge. Less than half lit, with the lit edge on the left in the Northern Hemisphere view, is a waning crescent. The same thin curve with its edge on the right would be a waxing crescent.

Questions people ask

What time of day can I see a waning crescent?

In the early morning, before sunrise. NASA says it rises in the very early morning and sets in the afternoon, before sunset. NASA's Scientific Visualization Studio describes it as low to the east before sunrise.

How long does the waning crescent phase last?

About a week, according to the Naval Observatory. It runs from last quarter, at an age of about 22.1 days, to New Moon at the end of the 29.5-day cycle.

Which side of a waning crescent is lit?

The left side in the Northern Hemisphere and the right side in the Southern Hemisphere, according to NASA.

Can I see a waning crescent in the evening?

No. NASA says it sets in the afternoon, before sunset. An evening crescent is a waxing crescent.

What comes after a waning crescent?

New Moon. The Naval Observatory says it begins a new cycle of phases. At New Moon the Moon rises and sets with the Sun, and NASA says it is not visible in the daytime sky.

Sources

• Moon Phases, NASA Science. https://science.nasa.gov/moon/moon-phases/. Opened November 10, 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 10, 2026.
• What Are the Moon’s Phases?, NASA Space Place. https://spaceplace.nasa.gov/moon-phases/en/. Opened November 10, 2026.
• Top Moon Questions, NASA Science. https://science.nasa.gov/moon/top-moon-questions/. Opened November 10, 2026.
• Moon Phase and Libration, 2026 South Up, NASA Scientific Visualization Studio. https://svs.gsfc.nasa.gov/5588. Opened November 10, 2026.
• Part 1: Lunar Phases, Imaging the Universe, Physics and Astronomy, The University of Iowa. https://itu.physics.uiowa.edu/labs/observational/moon-and-telescopes-i/part-1-lunar-phases. Opened November 10, 2026.
• Moon Viewing Tips, NASA Science. https://science.nasa.gov/moon/viewing-tips/. Opened November 10, 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

• Last Quarter MoonAt last quarter the Moon shows half its disk lit, and the lit part is shrinking.
• Waxing Crescent MoonA thin silver curve, low after sunset.