The United Arab Emirates (UAE) has a desert climate, with very mild winters and very hot and sunny summers, in which the humidity of the Persian Gulf makes the heat unbearable. The annual precipitation is almost everywhere below 100 millimetres (4 inches), and is concentrated in the winter months. The rains are rare, but they occur in the form of showers or downpours, which sometimes can be intense.
The country is made up of seven emirates, almost all overlooking the Persian Gulf (Abu Dhabi, Ajman, Dubai, Ras al-Khaimah, Sharjah and Umm al-Quwain), and one overlooking the Gulf of Oman (Fujairah). The biggest emirate, which also includes the capital, is Abu Dhabi, even though the most famous, because of its futuristic buildings and modern tourist resorts, is Dubai.
In Dubai, the daily average temperature goes from 19.5 degrees Celsius (67.5 °F) in January (so we are at the boundary between the subtropical and the tropical climate), to around 36.5 °C (98 °F) in August.
Here are the average temperatures of Dubai.
Dubai - Average temperatures
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Min (°C)151719222629313129252117
Max (°C)242629343940414239363126
Min (°F)596366727984888884777063
Max (°F)75798493102104106108102978879

In a typical year, only 98 millimetres (3.9 inches) of rain fall, most of which between December and March. In Abu Dhabi, still on the coast but more to the west, it rains even less, around 50 mm (2 in) per year.
Here is the average precipitation in Dubai.
Dubai - Average precipitation
MonthJanFebMarAprMayJunJulAugSepOctNovDecYear
Prec.(mm)1035251010000021598
Prec.(in)0.41.410.40000000.10.63.9
Days24420000000214

The sea in the Emirates is warm enough for swimming all year round, although from January to March it drops to 23 °C (73 °F); in summer it gets very warm, and it exceeds 30 °C (86 °F) from June to October, so as to allow long swims. On the Gulf of Oman, in winter the sea is a bit warmer than in the Persian Gulf. Here is the sea temperature in Dubai.
Dubai - Sea temperature
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Temp (°C)232323252931323332312825
Temp (°F)737373778488909190888277

Winter, from December to February, is very mild, or pleasantly warm: maximum temperatures range from 24 to 26 °C (76 to 80 °F). Sometimes, especially in January, cool air masses from the north can bring some cool and windy days, with night temperatures around 10/12 °C (50/54 °F), and daytime temperatures around 16/18 °C (61/64 °F).
Summer is very hot and sunny, with daytime temperatures ranging from 39 °C to 42 °C (101 to 107 °F) between June and September, and with the wind from the Persian Gulf that brings moist air from the sea, making the heat sweltering. April and October are also hot months, with highs around 34/36 °C (93/97 °F). During the hottest days the temperature can reach 47/48 °C (117/118 °F) on the coast, and even more in the interior.
Luckily, buildings are air-conditioned.

Abu Dhabi

In the northeast, the Al Hajar Mountains, which separate the coast of the Persian Gulf from that of the Gulf of Oman, the climate is still desert, although in the winter months it rains a bit more often than in the plain. Temperatures do not drop by much compared with the plain, except in the areas above 1,000 metres (3,300 feet), where it can get cold in winter, while in summer the heat is more bearable.
The south of the country, in the emirate of Abu Dhabi, is occupied by the vast sandy desert of the Rub al-Khali, and is almost uninhabited except in the oases, such as that of Liwa, and near oil and gas extraction facilities. Here the climate is similar to that of the coast, and even hotter in summer, but the air is drier because of the greater distance from the sea.

Emirates, desert

The sun in the Emirates shines all year round, sometimes however some cloud banks may pass, both in winter and in summer.
Dubai - Sunshine
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Hours88810111110101010108

All year round, but especially in spring, the United Arab Emirates may be affected by strong winds, which can bring dust and sand storms.

Tropical cyclones



Every now and then, the United Arab Emirates can be reached by tropical cyclones, which bring strong winds and heavy rains, though more rarely than in neighboring Oman, as happened with Cyclone Gonu in early June 2007. The area most at risk is the northern one, and in particular the emirate of Fujairah, being exposed on the coast of the Gulf of Oman; in contrast, the inland and western areas are generally spared. Cyclones form from May to December, and are more frequent at the beginning of the period (May-June), and a little less at the end (October-December).

When to go



The best time to visit the United Arab Emirates is winter, from December to February, which is a pleasant and sunny season. Thus, you will avoid the oppressive heat of the long summer months.
For a beach holiday, the best months are March and November (with a preference for the latter, because the sea is warmer), because when it gets too hot, even sunbathing can be a challenge.

What to pack



In winter, light clothes for the day, a sweater and jacket for the evening and for cool days, a scarf for the wind.
In summer: lightweight clothes, loose-fitting and made of natural fabric (cotton or linen), a desert turban, a sweatshirt and a scarf for air-conditioned places. For the reef, equipment for snorkeling, water shoes or rubber soled shoes.
For women, it is best to avoid shorts and miniskirts outside tourist resorts.