The very best time to visit the UAE is between September and May.
By September the summer heat is abating, although humidity can still be relatively high, blue skies are the norm and the evenings are warm. At this stage the tourist season is well under way.
Daytime temperatures are ideal during November, December, January and February (around 24 C), although the evenings can be a little cool. North-westerly winds (shamal) sometimes blow during these winter months, bringing choppy seas. Most of the annual rainfall occurs between December and March, but this tends to be in the form of short heavy downpours that rapidly clear away. Indeed some winters are totally dry.
By March–April, temperatures are beginning to increase during the day (early 30s), but humidity is still low and the evenings are warm. The mercury continues to rise during May (late-30s), peaking from June to August. July and August can be quite hot (high 40s) and humid (100 per cent). However hotels and golf clubs and other facilities offer very good deals during the summer months and it is worth remembering that hotels, shopping malls, in fact all buildings, cars, buses etc., are air-conditioned.