It will appear larger as it makes its closest approach to Earth in 18 years.
Scientists estimate the "supermoon" rising in the east at sunset will appear 14 percent bigger and 30 percent brighter at its peak.
Full moons vary in size because of the oval shape of its orbit, with one end closer to Earth. On Saturday, the moon will be 221,565 miles away — the closest to Earth since March 1993.
This celestial phenomenon should give people an excuse to take time out for the moon.
Usually, "most people are completely oblivious to its presence," said Geoff Chester of the U.S. Naval Observatory in Washington, D.C.
While Saturday's full moon will shine brighter than normal, it won't be as luminous as the near-supermoon of 2008 when it was higher in the sky, Chester said.
This type of full moon tends to bring a range of high and low tides, but experts say that's nothing to worry about. Nor is there any truth to the superstition that supermoons cause natural disasters.
"Nothing exciting is going to happen," Chester said.