The warmer-than-usual winter air has returned. Due to a solid El Niño pattern, temperatures have been breaking records all season. The weather phenomenon promotes a split-jet system that keeps the northern part of the country warm and the southern area slightly cooler. Overall temperatures have been at least 35 degrees Fahrenheit above normal.

However, the mid-January polar vortex brought stark contrast to the Northern Plains, with temperatures 30-40 degrees below normal for as many as 10 days. Currently, a ridge in the central and eastern U.S. should keep temperatures 5 to 15 degrees above normal throughout the remainder of February. Cooler air will attempt to make its way through later in the month but will likely be unable to kick El Niño’s strength.

Read more on winter weather patterns here.