The best time to visit Dubai is from November to March when it is the
so-called winter in Dubai. The Dubai winter is pleasant and suited for all kinds of outdoor activities. During this time, particularly during January and February, the city tends to get really crowded. The Dubai Shopping Festival, held during January and February, brings heavy tourist traffic which makes the city come alive. Hotel tariffs are high, airfare goes up, and everything seems a bit out of reach. But if you book early enough, you can avoid the hassles.
http://tandtravel.com/dubai/an-ultimate-guide-to-visit-the-iconic-burj-al-arab/