The Nadur Weather Observatory is located on the island of Gozo, situated at 36° 02' 26''N and 14° 17' 35''E, forming part of Malta, an independent state located approximately 90km south of Sicily in the centre of the Mediterranean Sea. The Maltese Islands have a typical Mediterranean climate with relatively mild, wet winters, and hot, extremely dry summers.

The 'winter' season usually commences between mid-September and early October, when the first heavy rains affect the islands. Depressions start making their way into the Mediterranean at this time of year, driven by the apparent southward movement of the overhead sun from the Equator to the Tropic of Cancer. This movement causes the three Hadley cells in the northern hemisphere to 'elongate' southwards. The descending limb of the Hadley cell nearest to the Equator which during the summer months gives an almost permanent high pressure over the Central Mediterranean region is replaced by the rising limb of the second Hadley cell (also known as the Ferrel Cell), which causes low pressures (depressions) to form over relatively low latitudes (30 - 50°N) over the Atlantic Ocean. These, then, travel eastwards to affect mainland Europe.

Some of them take a southeastwards trajectory and enter the Western Mediterranean, where they usually intensify due to the relatively warm sea temperatures which are maintained even during the winter months. Some depressions enter the Mediterranean from the Gulf of Lions and intensify over the Gulf of Genoa. Others form over the Sahara Desert and enter the Mediterranean from the southwest. All these affect the weather over the Maltese Islands by bringing rain, gales and sometimes severe weather, including severe gales, flooding rain, hail and thunderstorms.

Temperatures have never fallen below the freezing point in the Maltese Islands, at least since records started being taken in these islands approximately a century ago. However, in extreme cases, the period from December to February can contain very cold days (at least to the people of these islands!) with maximum daily air temperature sometimes reaching only 6 - 8°C and nighttime minimum temperature falling as low as 1 - 3°C. These cold snaps, when accompanied by high winds, drive the wind-chill temperatures down to well below freezing.

This state of affairs remains so until the middle to the latter part of March, when the overhead sun starts to make its run from the Equator to the Tropic of Cancer (23.5°N). The Hadley Cells start to 'contract' again, thus dragging with them the depressions to the northern latitudes. In fact one can say that the rainy season in the Maltese Islands ends by the end of March. April and May are characterised by changeable, but mostly fine weather conditions, with the occasional gale, thunderstorm and some rainfall. The hot, dry, summer season starts in earnest between late May and the middle of June, with cloudless skies, light winds and an almost total drought. It is not uncommon for the Maltese Islands to have no rain recorded whatsoever for over 100 days between the middle of May until late September or the middle of October. However, June still can have the solitary gale and shower at times.

Heatwaves are quite common during this season. Temperatures of over 35°C are considered as the norm especially during July and August. During the 1990s, temperatures of over 40°C have occurred almost annually. Humidity is quite high during the summer months, especially when the wind blows from the southern quadrants. High temperatures combined with high humidity make life unbearable in the Maltese Islands for those without any air-conditioning.

As stated above, the summer season then ends, usually abruptly with the first heavy thunderstorm, around the middle of September, although maximum air temperatures remain quite warm (22 - 26°C) until very late in October, and sometimes up until late November.

The prevailing wind in the Maltese Islands is the Northwesterly wind, known locally as the Majjistral. It blows for about a third of the year over these islands. During the hot summer months, winds are usually light and variable and a sea-breeze sets in from mid-morning to late afternoon.

Sea temperatures are quite mild all year round, with the lowest point reached in January and February (15°C) and the highest between late July and the middle of September (27°C).

Visibility is generally good all year round, especially in May and October, where excellent visibility is common. In fact on certain days during these months. Mount Etna, which lies about 200km to the NNE can be seen.