Your last chance to see a supermoon in 2025 is approaching quickly. December’s full moon is scheduled to appear on Dec. 4, exactly one week after Thanksgiving. Even if you don’t make plans to see it, you’ll probably see it anyway, as it’ll be the brightest thing in the night sky.
Don’t miss any of our unbiased tech content and lab-based reviews. Add CNET as a preferred Google source.
December’s Cold Moon is the third of four consecutive supermoons and the last one of 2025. Supermoons tend to come in packs of four thanks to how the moon orbits the Earth. The orbit is elliptical, meaning the moon is closer during some months and farther away in others. When it’s close to Earth, it’s referred to as perigee, and full moons during perigee are considered supermoons.
The apparent size difference between an average full moon and a supermoon can be subtle, but it’s there.
Since it is closer, the moon will be slightly bigger and brighter in the night sky. According to NASA, a supermoon is 14% larger and 33% brighter than a micro moon, which occurs during full moons when the moon is at its farthest point from Earth, a phenomenon known as apogee. Thus, it is the best time to view a full moon outside of special events like blood moons or lunar eclipses.
When is December’s full moon?
The Farmer’s Almanac reports that December’s full moon will take place on the evening of Dec. 4. It’ll reach peak illumination at 6:14 p.m. ET. Thanks to the recent daylight saving time change, it should be dark enough to see for most of the US, but if it isn’t, it’ll remain full all night. Those who can’t see it due to the weather can see a moon that is more than 90% full from Dec. 2-6.
You won’t need any special equipment to see the moon, as it’ll be the brightest thing in the night sky by a wide margin. Those who want to see more detail can certainly use a telescope or binoculars if they choose, which will make the moon’s various craters and textures easier to see.
December’s full moon is often referred to as the Cold Moon, as it typically occurs when the weather starts to become quite chilly. The moon is earning its name this time around, as a polar vortex is scheduled to hit the US during Thanksgiving and will stick around for a while afterward. The polar vortex will drive down temperatures in much of the US during the week of Dec. 1, so if you do go outside, make sure to bundle up.
