Houston has surprisingly good windsurfing weather. It's not Maui or the Gorge, but neither are 99% of the sailing locations in the U.S. This is a good place to learn windsurfing. Houston's moderate winds make it much easier to learn waterstarting, jibing and other beginning/intermediate skills. In 20 knots you can sail a big forgiving board and have a lot of time to think about what you are doing. In 30G40 conditions everything gets speeded up making learning more difficult. Most of the moderate to high wind days in Houston are generated by frontal systems. We generally get a few days of wind blowing out of the southeast before a front arrives. In the fall and winter, once the front passes through, we then get anywhere from 6 hours to 3 days of northerly wind.
Spring is Houston's prime windsurfing season. The weather is warm and the winds are generally blowing out of the southeast 15-20 knots 3-4 days a week. The season starts in March and ends in July with winds tapering off during the early part of summer. The wind generally doesn't start blowing until late afternoon and the sun doesn't set till 8:00pm. So, if you live close by, windsurfing after work is a possibility.
Late summer is the worst time to be windsurfing in Houston. At best, there are some light thermal generated winds in the afternoon. The air is hot and sticky during this period.
The fronts start to push though again. The wind pattern is similar to spring except the fronts start to reach all the way down to Houston. So we not only get the southeasterly wind, but also some stiff northern wind as well. The air and water temperatures are still high enough that you can get by with a shorty or light full wet suit. This is also the time for winds generated by tropical disturbances.
Much of the wind is coming out of the north. You can take advantage of some nuclear conditions during this season if you don't mind suiting up in the cold.