Only one beach to launch, with very gusty winds, not a very good place to launch. Boat launch is much better, but a boat is needed. Best spot to boat launch is in front of the dam.
The weather is very nice most time of the year, rains every day during rainy season about May to late September. Water is cold sometimes, you may need a shorty. Some people wear full wetsuits. But shorts only is no problem as well.
The wind is very gusty, and mostly light, with a lot of lulls. The wind normally varies from 4-14 knots. But some good sessions can be had once in a while. The wind 99% of the time comes from the same direction, a thermal is formed from the cold water, and warmer land behind the mountains. Very windy season, from about February to May. There are occasional cold fronts which bring very strong winds, but these are hit and miss.
Careful with boaters, sailboats, kayakers, etc. There are a lot of things to do, mountain biking, sailing, windsurfing, water skiing, kayaking, hiking, shopping, eating, paragliding (one of the best spots in Mexico), etc. Very nice little old style town, surrounded by mountains, very beautiful.