Dubai weather
Dubai has a subtropical arid climate and the weather is sunny all year round. Rainfall very rarely occurs and averages about 4 days a year.
Local residents believe the best time to visit Dubai is mid-October till the end of May. This is when temperatures average their coolest, a mere 25 degrees celsius!
In the summer months temperatures average 40 degrees celsius in July and very regularly climb above 45 degrees celsius! It is very important to drink large quantities of water and the health authorities recommend three or more litres a day. In the summer months it is advisable to stay out of the sun in the hottest periods 12pm-3pm, this is the ideal time to explore the wonderful shopping malls dotted around the city.
Always remember to put plenty of sun screen on and protect children from the sun and potential sunburn.
When booking the travel agents will not always advise you on the best time to travel to Dubai. Always remember the travel agent has no obligation unless you ask about temperatures. The summer months are so hot, it is advisable to plan your trip around visiting the air-conditioned malls as well as the beaches.
Source : http://www.dubai-livethedream.com/weather.html