UPDATE, Dec. 15: The shower seems to have peaked on schedule in the first half of December 14th Universal Time. Keep watch on its declining activity in the next few days.
UPDATE, Dec. 13: Early this morning observers were already counting 40 Geminids per hour under ideal conditions, according to the International Meteor Organization (IMO). See the IMO's graph of the shower's behavior, based on careful standardized-method amateur counts being reported from around the world.
Mention "meteors," and casual skywatchers usually think of the annual Perseid shower on display every August.
But the Geminid meteor shower of mid-December ties or even surpasses the Perseids as the year's richest and most reliable meteor display. Geminid meteors come from 3200 Phaethon, an asteroid discovered in 1983.
This year the Geminids are predicted to peak on the morning of December 14th around 11h UT, more or less. That's excellent timing for North America, especially out West. The Moon that night is only a day past first quarter and sets around midnight or 1 a.m. local time, depending on where you live. Even before then, on the evening of the 13th, the moonlight isn't bright enough to dampen the shower's visibility too much — and the Geminids, with their radiant near Castor and Pollux, pick up steam as early as 8 or 9 p.m. But the radiant is highest around 2 a.m., so the morning hours are the usually the most productive.
Bundle up as warmly as you possibly can, and lie back in a dark spot with an open sky. You may see as many as two meteors a minute on average if you have a very dark sky and are watching after midnight.
If your sky is not too light-polluted, you might try making a careful meteor count and reporting it to the International Meteor Organization. Such counts by amateurs supply much of what we know about meteor showers' behavior. For your count to be useful, you'll need to follow the procedures described on our page or at the IMO's website.
Don't forget that the shower lasts more than one night. Counts are especially needed on nights away from the maximum, because fewer people are watching. In any case, enjoy the show!