Is there more moonlight in winter than summer?

In nutshell, the answer is yes. But the reason is not just that winter nights are longer. The simple explanation is that the full or nearly full Moon is obviously in the opposite part of the sky from the Sun. When the moon is overhead, the Sun is directly beneath our feet, shining on the other side of the world. For this reason, the full Moon’s rising and setting behavior at any time of the year is just opposite to that of the Sun’s.

How does the Sun behave in the winter? It rises late, in the southeastern part of the sky, and sets early in the southwestern, thanks to our planet’s 23-degree tilt with respect to the plane of Earth’s orbit. If there were no tilt, the sun would always be overhead somewhere on the equator, and seasons would be unknown on Earth. The tilt means that high noon brings the Sun overhead during a year in a wide band between the Tropic of Cancer and Tropic of Capricorn (thus, tropical latitudes are defined as areas where the Sun is directly overhead sometime during year). Between the first day of spring and the first day of autumn, the Sun is north of the equator, more nearly overhead for us. It stays above the horizon longer, and we get more sunlight. The other half of the year brings the reverse; many of us travel both to and from work or school in darkness.

Remember, though, that the full Moon’s behavior is opposite that of the Sun. On a moonlit summer night, the Moon is overhead somewhere south of the equator. For us, it is above the horizon for a relatively short time. And in winter, the situation is opposite. The Moon is up longer; we get more moonlit hours.

More reading:
Moonlight (Wikipedia)

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