There are three factors behind the toasty temperatures we’ve experienced to kick off 2026 in San Antonio.
SAN ANTONIO — Holiday weather was unusually warm, prompting many to remark: “It just doesn’t feel like Christmas.”
Warmer-than-average temperatures have kept Frosty in the freezer so far, and you shouldn’t let your guard down yet.
2026 got underway with an afternoon high of 74 degrees Thursday—not quite a record-high (that came in 2006, when it reached 83 degrees), but much warmer than San Antonio’s typical January high of 63.3 degrees.
Friday marked another day of major heat, and this time records were met: The mercury reached 89 degrees at 3:19 p.m., continuing our unusually toasty winter. That sets a new record for Jan. 2, breaking the 86-degree mark from 2006, and ties the all-time January high in San Antonio.
The average December high in San Antonio was 69.4 degrees, meanwhile, about five degrees warmer than usual.
So what’s behind it? Meteorologists point to three main factors.
First: the overall weather pattern, particularly the jet stream. For much of the winter, high pressure has remained parked over Texas, while the jet stream has stayed more active to the north and west. That setup has kept colder systems farther north and allowed warmer air to linger over the state, resulting in quieter and warmer conditions than normal.
The second factor: cloud cover. Texas has seen frequent clouds during the overnight and early morning hours. That cloud cover acts like an insulating blanket, trapping warmth near the surface overnight.
During the day, this cloud cover would typically limit warming. But we’ve seen more cloud cover lately in the evenings and mornings, with more sun in the days and afternoons allowing for more extended warming. That’s a typical pattern we’d see during the summer months, when the heat is extreme.
Finally, La Niña is playing a role. La Niña is marked by cooler-than-average sea temperatures in the tropical Pacific, which often brings warmer and drier conditions to Texas during the fall and winter. Due to the lack of precipitation, the risk of drought increases, which is what is happening right now for much of the Lone Star State.
Remember, even in a warm winter, it only takes one brief pattern change to kick the warm air out and bring in the polar vortex, flipping winter on its head, bringing back memories of February 2021.