December started off relatively calm, coming down from the extreme flooding events in November. FEMA was ready to bring relief to approximately 700 people in the Central Texas area. On December 12, there was an EF2 tornado around Willis that uprooted trees, and damaged an estimated 50 homes, and the Lindale mayor declared the area a disaster area. The storm also had straight line winds which blew down 64 empty train cars from an overpass on Angelina and Neches River Railroad overpass. The December 26 storm system caused 12 tornadoes, 7 EF-0 tornadoes, 2 EF-1, and one each of EF-2, EF-3, and EF-4. This year saw the highest number of reported tornadoes in North Central Texas 76 , beating the previous record of 73 in 1994. Prior to this event, 2015 only recorded 10 deaths due to tornado activity; 11 people lost their lives during the storm and the total damage estimated cost was 1.2 billion dollars.

In addition to the tornadoes and other severe weather, Texans also experienced blizzards, snowstorms and other wintery weather. El Paso, which is not known for having unusual weather, experienced white-out conditions at the Sun Bowl. The southern High Plains and Low Rolling Plains also experienced blizzard conditions. Overall, about 16 inches of snow was measured in Midland, and 10.3 inches in Lubbock with snow drifts up to 6 feet. Roads closed included Interstates 10, 20 and 40 along with large numbers of state and U.S. highways. The combination of the blizzard and severe weather in North Texas made for difficult travel post-Christmas for people traveling by airplane: the weather caused 620 flights cancellations and 625 delays in the DFW International Airport along with other flight delays in smaller airports, contributing to an estimated half of all flights in and out of Texas being cancelled.

By the end of the year, 2015 was the wettest year on record for Texas. The major flooding and wet periods of 2015 were in May and October. These beat the previous record from 1895. This excess rain put an end to the five year drought. The Lone Star State was drought free for all of December, with just a slight increase in the areas with Abnormal Dryness (D0) throughout the month.