Dubai demands that you dress differently, during different times of the year. Let me start with summer. Dubai, during summer, is one of the hottest places on the planet. Temperatures can reach up to 50 degrees Celsius. This means that walking out on the roads is literally impossible, if you are accustomed to the cold climate of the US and Europe. If you are an Asian or Australian, you have better chances of surviving the heat, though you will have to do so by biting your teeth.

So the only other way out is to dress smart. During summer, trousers are a no-no. Always stick to shorts. Wearing sleeveless clothes is a good idea, but if you are prone to sunburns, then refrain from doing so.
But shorts and sleeveless clothes are considered offensive by some locals, so you had better dress so at your discretion.
Wear airy slippers but ensure that the padding is thick to ensure that the heat from the ground does not seep into your feet.
When you go to the desert, my advice is that you do not wear shoes and instead wear sandals. The reason being, all the sand will go into your shoes and it is a pain in the neck to clear it out.

Anyways, I dont think anyone in their sane minds will venture out into the desert in the middle of the summer season in Dubai. It is suicidal to do that.
Now, if you visit during Nov or Dec, the weather is pretty pleasant. It is pretty much like Texas during the day but it does get chill during the night. Pack those leather jackets and silk clothes because now would be a good time to use them.
Drink a lot of water because many people might face dehydration while traveling because Dubai is situated in the heart of the desert. The advantage in Dubai is that all the buildings, cars,buses and hotels are air-conditioned so when you are indoors, there is nothing to worry about. In fact, you can even pay a visit to Ski Dubai at the Mall of the Emirates!