1,321. Calculating the Moon's Latitude

Hilchos Kiddush HaChodesh 16:9

The latitude of the moon is never more than five degrees to the north or the south. The moon proceeds as follows: it starts at the head and deviates from the sun’s orbit a little bit until it reaches five degrees. At this point, it starts to get closer; it has no latitude when it reaches the tail. It then deviates again until it reaches five degrees. It then approaches the sun’s orbit until it again has no latitude.

Hilchos Kiddush HaChodesh 16:10

If you want to know the moon’s latitude, and whether it is to the north or the south, you must first, calculate the position of the head and the actual position of the moon for the date in question. Subtract the head’s position from the moon’s actual position. The result is called the course of the latitude. If the course of the latitude is from one to 180 degrees, the latitude of the moon is to the north; if it’s more than 180 degrees, the latitude of the moon is to the south. When the course is exactly 180 or 360 degrees, the moon has no latitude. Next, calculate the angle for the course of the latitude; this will tell us how far north or south the moon is inclined.