The biggest difference that I've noticed in 11 years of living in Texas (practically Oklahoma) how long during the day it maintains 85 degrees. Alabama typically cools down earlier in the afternoon and doesn't get hot as quickly in the day. Texas for whatever reason, starts out hot and lasts longer.
Example...
http://weatherspark.com/history/29922/2012/College-Station-Texas-United-States
The full year of hourly temperature reports with the days of the year on the horizontal and the hours of the day on the vertical. The hourly temperature measurement is color coded into meaningful temperature bands: frigid is purple (below 15°F), freezing is blue (15°F to 32°F), cold is dark green (32°F to 50°F), cool is light green (50°F to 65°F), comfortable is yellow (65°F to 75°F), warm is light red (75°F to 85°F), hot is medium red (85°F to 100°F), sweltering is dark red (above 100°F), and missing data is pink.
The daily low (blue) and high (red) temperature during 2012 with the area between them shaded gray and superimposed over the corresponding averages (thick lines), and with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile). The bar at the top of the graph is red where both the daily high and low are above average, blue where they are both below average, and white otherwise.
http://weatherspark.com/history/31749/2012/Tuscaloosa-Alabama-United-States