[SAN DIEGO (Citywide) Thurs Dec 4, 2025, 7:00 p.m.]
SAN DIEGO — December’s Cold Moon, the final full moon before the winter solstice, rose over the region Thursday evening and quickly climbed high into the sky — a normal December pattern that makes this moon brighter and longer-lasting than most others in the year.
Also known as the Long Night Moon, tonight’s full moon arrives during some of the longest nights of the season and is expected to amplify coastal high tides. Skies stayed mostly clear over San Diego, giving residents sharp views as the moon moved above downtown and the bay.
And as with every full moon, the old question returns: Do people act differently when it’s this bright? Researchers have never reached a firm consensus — some studies find no measurable effect, while others note slight upticks in nighttime activity or sleep disruption. But first responders, hospital workers and even some police officers often talk anecdotally about busier nights when the moon is full.
Whether the Cold Moon actually changes behavior or simply raises awareness of unusual events, it remains one of the most watched and debated sky moments of the year.
