January wasn't supposed to be a record-setter.
Last month was expected to continue a fall out of record high global heating conditions that began last September. But that's not how things turned out.
According to the first of several analyses coming in the next couple of weeks, last month was the warmest January on record.
The first three weeks of the year saw particularly high global temperatures, according to climate scientist Zeke Hausfather, writing in his newsletter The Climate Brink. Then, with a few days left in the month, temperatures finally fell out of record territory. But by then the die was cast.
January 2025 finished considerably warmer overall than January 2024, the previous record-holder. Back then, global temperatures seemed shockingly warm. But at least we could place some of the blame on El Niño, a climate phenomenon that tends to warm things up. Its influence also was in place during other record-setting Januaries: 2007, 2016 and 2020.
But we don't have El Niño to kick around anymore. It actually dissipated months ago. Adding to the puzzle is the fact that we're in the midst of a La Niña, which typically cools things down.
All things being equal, this should have resulted in lower global temperatures, says Hausfather, Senior Fellow at the Breakthrough Institute. But this past January, things apparently weren't equal. Why? That remains unclear.
"Global temperature over the past few months have exceeded, or been at the upper end, of what we’ve seen after any other El Niño event in the historical record," Hausfather writes.
But Hold on, What About That Wicked Cold Snap?
If you live in Canada or the lower 48 states of the United States, you might be wondering how this could possibly be true given the brutal Arctic blast that overtook most of North America on January 20 and 21. I shivered through it, and tens of millions of other people did as well.
But If you live in Alaska, January's record warmth might make perfect sense given the unusually high temperatures there during the same period. In fact, most of the rest of the world was anomalously warm even as the blast of cold Arctic air descended on much of the U.S. and Canada.
So please remember this: weather ≠ climate. Weather is about atmospheric conditions over the short run and at a specific time and place. And climate is about how weather adds up over a longer period and over broad geographical areas.
What to expect moving forward? Weather models predict sharp cooling in the Northern Hemisphere in the short term. This lowers the odds that February will also set a new monthly global heating record, according to Hausfather. "But an unexpected record to start things off may presage higher temperatures this year than many of us thought."
