Below-average precipitation across the West led to an expansion of drought.
It was the sixth-warmest year on record for planet Earth.
The month brought a warm West and a cold East. Amid widespread dryness, wetter-than-average conditions occurred in Colorado, the Ohio Valley, and the Mid-Atlantic.
It's been 45 years since the planet had a cooler-than-average year.
NOAA National Centers for Environmental Information recaps the 2021 climate for the United States.
A cool, wet January is slightly favored across much of the North, with a warm, dry month favored for the South. Elsewhere, there are even chances for any outcome.
Use this interactive map to browse a collection of animated gifs showing monthly sea level at U.S. tide-monitoring stations over their lifetimes.
The fingerprints of La Niña were all over the global precipitation map.
But fires and other disturbances create patches of "browning" in satellites' view of Arctic vegetation.