The closest place to Dallas is Clear Springs Scuba Park. It's a flooded limestone quarry with all the typical quarry stuff. Sunken boats, airplane, etc. It's a 45 minute drive east of downtown Dallas outside a small town called Terrell.
Lake Murray in southern Oklahoma is about an hour and a half drive north. It has some interesting dives near the dam and at Tucker Tower.
Lake Travis is in Austin, about 3 and a half hours south. You can dive at Mansfield Dam, Windy Point or you could do some dives with the Giant Stride. It's the local dive boat. Rates are very reasonable and they can take you to a lot of sites that are inaccessible from shore.
Lake Broken Bow is in southeast Oklahoma. About 3 hours north east of Dallas. It has some nice dives near the Spillway Dam and on the outside of the island at Stephens Gap.
Now for the water temperature. I've got good news and I've got bad news. The temperature at all of these in January is going to be in the 40's. That's about 5C for you Imperial System challenged folks. Drysuit is highly recommended although I have known a few brave souls get in a 20-25 minute dive in heavy neoprene. Travis will be a little warmer but not much. Maybe some of the Austin folks will chime in with mid-winter temps down there.
The good news is that due to the cold water, all of the algae dies back so you get some of the best visibility of the year.
Good luck in your search!