you can surf on http://www.windtarifa.com
to find what you're looking for.
However i'd like to say something you could not find on this site: wind conditions are various depending on the season you choose.Usually,there are very few days without wind!!! i.e. during summer you can surf a 10knots "PONIENTE" with a wakeboard and a 12m3 (or a big directional and a 9m3 if you prefer)to a massive 40knots "LEVANTE"...Last year I stayed in Tarifa from July 15th to August 30th and i surfed every day;if this is not enough think about summer is the worst period for wind (but the best for parties!) I hope to meet u there!